func_code_string: #include <algorithm>   #include <bitset>   #include <cmath>   #include <complex>   #include <cstdio>   #include <iostream>   #include <map>   #include <numeric>   #include <queue>   #include <random>   #include <set>   #include <stack>   #include <string>   #include <sys/types.h>   #include <unistd.h>   #include <unordered_map>   #include <unordered_set>   #include <vector>      #pragma region macros   #define _overload(_1, _2, _3, name, ...) name   #define _rep(i, n) _range(i, 0, n)   #define _range(i, a, b) for (int i = int(a); i < int(b); ++i)   #define rep(...) _overload(__VA_ARGS__, _range, _rep, )(__VA_ARGS__)   #define _rrep(i, n) _rrange(i, n, 0)   #define _rrange(i, a, b) for (int i = int(a) - 1; i >= int(b); --i)   #define rrep(...) _overload(__VA_ARGS__, _rrange, _rrep, )(__VA_ARGS__)   #pragma endregion macros      using namespace std;      template <class T> bool chmax(T &a, const T &b) {       return (a < b) ? (a = b, 1) : 0;   }   template <class T> bool chmin(T &a, const T &b) {       return (b < a) ? (a = b, 1) : 0;   }      using ll    = long long;   using R     = long double;   const R EPS = 1e-9L;  // [-1000,1000]->EPS=1e-8 [-10000,10000]->EPS=1e-7   inline int sgn(const R &r) {       return (r > EPS) - (r < -EPS);   }   inline R sq(R x) {       return sqrt(max(x, 0.0L));   }      const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};   const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};      const pid_t pid = getpid();   // Problem Specific Parameter:      ll p[1010][1010];   ll psum[1010];   ll p2sum[1010];      int main(void) {       std::cin.tie(0);       std::ios::sync_with_stdio(false);          int m, k;       cin >> m >> k;          rep(i, k) {           rep(j, m) {               cin >> p[i][j];               psum[i] += p[i][j];               p2sum[i] += 1LL * p[i][j] * p[i][j];           }       }             const ll vsum = (psum[k - 1] - psum[0]) / (k - 1);       ll y          = -1;          rep(i, 1, k - 1) {           const ll v = (psum[i] - psum[i - 1]);           if (v != vsum) {               y = i;               break;           }       }          ll x;       rep(j, m) {           const ll v      = (psum[y] - psum[y - 1]);           const ll modify = vsum - v;              p2sum[y] -= p[y][j] * p[y][j];           p[y][j] += modify;           p2sum[y] += p[y][j] * p[y][j];              set<ll> s;           rep(i, 1, k - 1) {               const ll d2 = (p2sum[i - 1] + p2sum[i + 1]) - 2LL * p2sum[i];               s.insert(d2);           }              if (s.size() == 1) {               x = p[y][j];               break;           }              p2sum[y] -= p[y][j] * p[y][j];           p[y][j] -= modify;           p2sum[y] += p[y][j] * p[y][j];       }          cout << y <<     << x << endl;       return 0;   }