func_code_string: #include <bits/stdc++.h>   using namespace std;   inline int in() {     int x;     scanf( %d , &x);     return x;   }   template <typename T>   inline istream& operator>>(istream& i, vector<T>& v) {     for (int j = 0; j < ((int)(v).size()); ++j) i >> v[j];     return i;   }   template <typename T>   string join(const vector<T>& v) {     stringstream s;     for (int i = 0; i < ((int)(v).size()); ++i) s <<     << v[i];     return s.str().substr(1);   }   template <typename T>   inline ostream& operator<<(ostream& o, const vector<T>& v) {     if ((int)(v).size()) o << join(v);     return o;   }   template <typename T1, typename T2>   inline istream& operator>>(istream& i, pair<T1, T2>& v) {     return i >> v.first >> v.second;   }   template <typename T1, typename T2>   inline ostream& operator<<(ostream& o, const pair<T1, T2>& v) {     return o << v.first <<  ,  << v.second;   }   template <typename T>   inline long long int suma(const vector<T>& a) {     long long int res(0);     for (auto&& x : a) res += x;     return res;   }   const double eps = 1e-10;   const long long int LINF = 1001002003004005006ll;   const int INF = 1001001001;   const int MX = 200005;   const int B = 9;   inline long long int ten(int n) { return n ? ten(n - 1) * 10 : 1; }   const int BS = ten(B);   struct bint;   istream& operator>>(istream& i, bint& a);   ostream& operator<<(ostream& o, const bint& a);   struct bint {     vector<int> d;     bool sg;     bint(long long int n = 0) {       sg = n < 0;       if (sg) n = -n;       while (n) {         d.push_back(n % BS);         n /= BS;       }     }     bint(const string& s) {       sg = s[0] ==  - ;       int si = sg;       for (int i = (int)(s).size(); i > si; i -= B) {         d.push_back(0);         for (int j = max(si, i - B); j < i; ++j)           d.back() = d.back() * 10 + (s[j] -  0 );       }       cut();     }     bint(const vector<int>& d, bool sg = false) : d(d), sg(sg) {}     inline bint& cut() {       while ((int)(d).size() && !d.back()) d.pop_back();       sg &= !iszero();       return *this;     }     inline int size() const { return (int)(d).size(); }     inline int& operator[](int i) { return d[i]; }     inline const int& operator[](int i) const { return d[i]; }     inline int len() const {       if (!(int)(d).size()) return 0;       int l = ((int)(d).size() - 1) * B;       int b = d.back();       while (b) ++l, b /= 10;       return l;     }     bint abs() const {       bint a(*this);       a.sg = false;       return a;     }     inline bool iszero() const { return !(int)(d).size(); }     long long int toLL() const {       if (bint(INF) < abs()) return sg ? -INF : INF;       long long int x = 0;       for (int i = ((int)(d).size()) - 1; i >= 0; --i) x = x * BS + d[i];       if (sg) x = -x;       return x;     }     bint& _add(const bint& a) {       if ((int)(d).size() <= (int)(a).size())         d.resize((int)(a).size() + 1);       else         d.push_back(0);       int i = 0;       while (i < (int)(a).size()) {         d[i] += a[i];         if (d[i] >= BS)           d[i] -= BS, ++d[++i];         else           ++i;       }       while (d[i] == BS) d[i] = 0, ++d[++i];       if (!d.back()) d.pop_back();       return *this;     }     bint& _asub(const bint& a) {       int i = 0;       while (i < (int)(a).size()) {         d[i] -= a[i];         if (d[i] < 0)           d[i] += BS, --d[++i];         else           ++i;       }       if (i < (int)(d).size())         while (d[i] == -1) d[i] = BS - 1, --d[++i];       return cut();     }     bint& _sub(const bint& a) {       if (_cmp(a)) {         bint b(a);         swap(*this, b);         return _asub(b);       }       return _asub(a);     }     bint& operator+=(const bint& a) {       if (sg == a.sg) return _add(a);       return _sub(a);     }     bint& operator-=(const bint& a) {       if (sg != a.sg) return _add(a);       sg ^= 1;       _sub(a);       if (!iszero()) sg ^= 1;       return *this;     }     bint& operator*=(long long int a) {       if (!a) return *this = 0;       if (a < 0) sg ^= 1, a = -a;       if (LINF / BS < a) return (*this) *= bint(a);       long long int x = 0;       for (int i = 0; i < ((int)(d).size()); ++i) {         x += a * d[i];         d[i] = x % BS;         x /= BS;       }       while (x) d.push_back(x % BS), x /= BS;       return *this;     }     bint mult(const bint& a) const {       if ((int)(a).size() == 1) return bint(*this) *= a[0];       if (a.iszero()) return 0;       bint b = (*this) * a.d.back();       b.sg ^= a.sg;       for (int i = ((int)(a).size() - 1) - 1; i >= 0; --i) {         b.d.insert(b.d.begin(), 0);         b += (*this) * a[i];       }       return b;     }     long long int operator%(long long int a) const {       assert(a > 0);       long long int r = 0;       for (int i = ((int)(d).size()) - 1; i >= 0; --i) r = (r * BS + d[i]) % a;       if (sg) r = (a - r) % a;       return r;     }     bint& operator/=(long long int a) {       assert(a);       if (a < 0) sg ^= 1, a = -a;       assert(LINF / BS >= a);       long long int x = 0;       for (int i = ((int)(d).size()) - 1; i >= 0; --i) {         x = x * BS + d[i];         d[i] = x / a;         x %= a;       }       return cut();     }     bint operator+(const bint& a) const { return bint(*this) += a; }     bint operator-(const bint& a) const { return bint(*this) -= a; }     bint operator*(long long int a) const { return bint(*this) *= a; }     bint operator*(const bint& a) const;     bint& operator*=(const bint& a) { return *this = (*this) * a; }     bint operator/(long long int a) const { return bint(*this) /= a; }     bint operator/(const bint& a) const {       assert(false);       return bint();     }     bint operator%(const bint& a) const {       assert(false);       return bint();     }     bint square() const;     bint ex(long long int t) const {       if (!t) return 1;       bint a = ex(t >> 1).square();       if (t & 1) return a * (*this);       return a;     }     bool _cmp(const bint& a) const {       if ((int)(d).size() != (int)(a).size())         return (int)(d).size() < (int)(a).size();       for (int i = ((int)(d).size()) - 1; i >= 0; --i)         if (d[i] != a[i]) return d[i] < a[i];       return false;     }     bool operator<(const bint& a) const {       if (sg != a.sg) return sg;       return sg ? a._cmp(*this) : _cmp(a);     }     bool operator<=(const bint& a) const { return !(a < (*this)); }     bool operator==(const bint& a) const { return sg == a.sg && d == a.d; }     string str() const {       if (!(int)(d).size()) return  0 ;       ostringstream os;       if (sg) os <<  - ;       os << d.back();       for (int i = ((int)(d).size() - 1) - 1; i >= 0; --i)         os << setw(B) << setfill( 0 ) << d[i];       return os.str();     }   };   long long int extgcd(long long int a, long long int b, long long int& x,                        long long int& y) {     for (long long int u = y = 1, v = x = 0; a;) {       long long int q = b / a;       swap(x -= q * u, u);       swap(y -= q * v, v);       swap(b -= q * a, a);     }     return b;   }   long long int mod_inv(long long int a, long long int m) {     long long int x, y;     extgcd(a, m, x, y);     return (m + x % m) % m;   }   long long int mod_pow(long long int a, long long int n, long long int mod) {     long long int ret = 1;     long long int p = a % mod;     while (n) {       if (n & 1) ret = ret * p % mod;       p = p * p % mod;       n >>= 1;     }     return ret;   }   template <int mod, int primitive_root>   struct NTT {     int get_mod() const { return mod; }     void _ntt(vector<int>& a, int sign) {       const int n = (int)(a).size();       int h = mod_pow(primitive_root, (mod - 1) / n, mod);       if (sign == -1) h = mod_inv(h, mod);       int i = 0;       for (int j = 1; j < n - 1; ++j) {         for (int k = n >> 1; k > (i ^= k); k >>= 1)           ;         if (j < i) swap(a[i], a[j]);       }       for (int m = 1; m < n; m *= 2) {         const int m2 = m * 2;         const long long int base = mod_pow(h, n / m2, mod);         vector<long long int> w(m);         w[0] = 1;         for (int j = 1; j < m; ++j) w[j] = w[j - 1] * base % mod;         for (int s = 0; s < n; s += m2) {           for (int x = 0; x < (m); ++x) {             int j = s + x;             int d = a[j + m] * w[x] % mod;             a[j + m] = a[j] - d;             if (a[j + m] < 0) a[j + m] += mod;             a[j] -= mod - d;             if (a[j] < 0) a[j] += mod;           }         }       }     }     void ntt(vector<int>& input) { _ntt(input, 1); }     void intt(vector<int>& input) {       _ntt(input, -1);       const int n_inv = mod_inv((int)(input).size(), mod);       for (auto& x : input) x = (long long int)x * n_inv % mod;     }     vector<int> convolution(const vector<int>& a, const vector<int>& b) {       int ntt_size = 1;       while (ntt_size < (int)(a).size() + (int)(b).size()) ntt_size *= 2;       vector<int> _a = a, _b = b;       _a.resize(ntt_size);       _b.resize(ntt_size);       ntt(_a);       ntt(_b);       for (int i = 0; i < (ntt_size); ++i)         _a[i] = (long long int)_a[i] * _b[i] % mod;       intt(_a);       _a.resize((int)(a).size() + (int)(b).size());       return _a;     }     vector<int> square(const vector<int>& a) {       int ntt_size = 1;       while (ntt_size < (int)(a).size() * 2) ntt_size *= 2;       vector<int> _a = a;       _a.resize(ntt_size);       ntt(_a);       for (int i = 0; i < (ntt_size); ++i)         _a[i] = (long long int)_a[i] * _a[i] % mod;       intt(_a);       _a.resize((int)(a).size() * 2);       return _a;     }   };   const int P1 = 1811939329;   const int P2 = 2013265921;   const int P3 = 2113929217;   const long long int P12 = (long long int)P1 * P2;   const int IP1_2 = mod_inv(P1, P2);   const int IP12_3 = mod_inv(P12, P3);   const long long int P12_R = P12 % BS;   const long long int P12_Q = P12 / BS;   vector<int> _garner(vector<int>& x, vector<int>& y, vector<int>& z) {     long long int c = 0;     for (int i = 0; i < ((int)(x).size()); ++i) {       y[i] = ((long long int)y[i] - x[i] + P2) * IP1_2 % P2;       long long int s = x[i] + (long long int)y[i] * P1;       z[i] = (z[i] - s % P3 + P3) * IP12_3 % P3;       s += c + P12_R * z[i];       c = P12_Q * z[i] + s / BS;       x[i] = s % BS;     }     return x;   }   bint bint::operator*(const bint& a) const {     if ((int)(a).size() <= 10) return mult(a);     NTT<P1, 13> ntt1;     NTT<P2, 31> ntt2;     NTT<P3, 5> ntt3;     vector<int> x = ntt1.convolution(d, a.d);     vector<int> y = ntt2.convolution(d, a.d);     vector<int> z = ntt3.convolution(d, a.d);     return bint(_garner(x, y, z), sg ^ a.sg).cut();   }   bint bint::square() const {     NTT<P1, 13> ntt1;     NTT<P2, 31> ntt2;     NTT<P3, 5> ntt3;     vector<int> x = ntt1.square(d);     vector<int> y = ntt2.square(d);     vector<int> z = ntt3.square(d);     return bint(_garner(x, y, z), false).cut();   }   istream& operator>>(istream& i, bint& a) {     string s;     i >> s;     a = bint(s);     return i;   }   ostream& operator<<(ostream& o, const bint& a) { return o << a.str(); }   long long int n;   int cnt;   int f(long long int i, long long int j) {     i = n - i;     j = n - j;     cout << i <<     << j << endl;     int res;     cin >> res;     ++cnt;     return res;   }   bint area(pair<long long int, long long int> s,             pair<long long int, long long int> t) {     return bint(t.first - s.first) * (t.second - s.second);   }   int main() {     cin >> n;     pair<long long int, long long int> s(0, 0);     pair<long long int, long long int> t(n, n);     pair<long long int, long long int> x(0, 0);     while (1) {       bint a = (area(s, t) - area(s, x)) / 3 + 1;       long long int i, j;       {         long long int l = x.first, r = t.first;         while (l + 1 < r) {           long long int c = (l + r) >> 1;           if (area(pair<long long int, long long int>(c, s.second), t) < a)             r = c;           else             l = c;         }         i = l;       }       {         long long int l = x.second, r = t.second;         while (l + 1 < r) {           long long int c = (l + r) >> 1;           if (area(pair<long long int, long long int>(s.first, c), t) < a)             r = c;           else             l = c;         }         j = l;       }       int res = f(i, j);       if (!res) break;       if (res == 1) {         t.first = i;       } else if (res == 2) {         t.second = j;       } else {         x = pair<long long int, long long int>(i + 1, j + 1);       }       if (x.first >= t.first) s.second = x.second, x = s;       if (x.second >= t.second) s.first = x.first, x = s;     }     cerr << cnt << endl;     return 0;   }   