func_code_string: #include <bits/stdc++.h>   using namespace std;   const double PI = acos(-1);   const double eps = 1e-9;   const int inf = 2000000000;   const long long infLL = 9000000000000000000;   inline bool checkBit(long long n, int i) { return n & (1LL << i); }   inline long long setBit(long long n, int i) { return n | (1LL << i); }   inline long long resetBit(long long n, int i) { return n & (~(1LL << i)); }   int dx4[] = {0, 0, +1, -1};   int dy4[] = {+1, -1, 0, 0};   int dx8[] = {+1, 0, -1, 0, +1, +1, -1, -1};   int dy8[] = {0, +1, 0, -1, +1, -1, +1, -1};   inline bool EQ(double a, double b) { return fabs(a - b) < 1e-9; }   inline bool isLeapYear(long long year) {     return (year % 400 == 0) || (year % 4 == 0 && year % 100 != 0);   }   inline bool isIntege(double num) { return (num == (int)num); }   inline bool collinear(int x1, int y1, int x2, int y2, int x3, int y3) {     return (y1 - y2) * (x1 - x3) == (y1 - y3) * (x1 - x2);   }   inline double coDist(double x1, double y1, double x2, double y2) {     return sqrt(((x1 - x2) * (x1 - x2)) + ((y1 - y2) * (y1 - y2)));   }   inline double TriangleAreaWithSide(double a, double b, double c) {     double s = (a + b + c) / 2;     double area = sqrt(s * (s - a) * (s - b) * (s - c));     return area;   }   inline double area3(double x1, double y1, double x2, double y2, double x3,                       double y3) {     double A = abs((x1 * y2 + x2 * y3 + x3 * y1) - (y1 * x2 + y2 * x3 + y3 * x1));     A /= 2.0;     return A;   }   inline long double degreetoradian(long double x) {     long double val = PI * x;     val /= (180.0);     return val;   }   inline void normal(long long &a) {     a %= 1000000007;     (a < 0) && (a += 1000000007);   }   template <typename T>   inline T gcd(T a, T b) {     T c;     while (b) {       c = b;       b = a % b;       a = c;     }     return a;   }   inline long long modMul(long long a, long long b) {     a %= 1000000007, b %= 1000000007;     normal(a), normal(b);     return (a * b) % 1000000007;   }   inline long long modAdd(long long a, long long b) {     a %= 1000000007, b %= 1000000007;     normal(a), normal(b);     return (a + b) % 1000000007;   }   inline long long modSub(long long a, long long b) {     a %= 1000000007, b %= 1000000007;     normal(a), normal(b);     a -= b;     normal(a);     return a;   }   inline long long modPow(long long b, long long p) {     long long r = 1;     while (p) {       if (p & 1) r = modMul(r, b);       b = modMul(b, b);       p >>= 1;     }     return r;   }   inline long long modInverse(long long a) { return modPow(a, 1000000007 - 2); }   inline long long modDiv(long long a, long long b) {     return modMul(a, modInverse(b));   }   inline bool equalTo(double a, double b) {     if (fabs(a - b) <= eps)       return true;     else       return false;   }   inline bool notEqual(double a, double b) {     if (fabs(a - b) > eps)       return true;     else       return false;   }   inline bool lessThan(double a, double b) {     if (a + eps < b)       return true;     else       return false;   }   inline bool lessThanEqual(double a, double b) {     if (a < b + eps)       return true;     else       return false;   }   inline bool greaterThan(double a, double b) {     if (a > b + eps)       return true;     else       return false;   }   inline bool greaterThanEqual(double a, double b) {     if (a + eps > b)       return true;     else       return false;   }   inline string to_s(int t) {     stringstream ss;     ss << t;     return ss.str();   }   struct edge {     int p, q, w;   };   bool cmp(edge &a, edge &b) { return a.w < b.w; }   template <typename first, typename second>   ostream &operator<<(ostream &os, const pair<first, second> &p) {     return os <<  (  << p.first <<  ,   << p.second <<  ) ;   }   template <typename T>   ostream &operator<<(ostream &os, const vector<T> &v) {     os <<  { ;     for (auto it = v.begin(); it != v.end(); ++it) {       if (it != v.begin()) os <<  ,  ;       os << *it;     }     return os <<  } ;   }   template <typename T>   ostream &operator<<(ostream &os, const set<T> &v) {     os <<  [ ;     for (auto it = v.begin(); it != v.end(); ++it) {       if (it != v.begin()) os <<  ,  ;       os << *it;     }     return os <<  ] ;   }   template <typename T>   ostream &operator<<(ostream &os, const multiset<T> &v) {     os <<  [ ;     for (auto it = v.begin(); it != v.end(); ++it) {       if (it != v.begin()) os <<  ,  ;       os << *it;     }     return os <<  ] ;   }   template <typename first, typename second>   ostream &operator<<(ostream &os, const map<first, second> &v) {     os <<  [ ;     for (auto it = v.begin(); it != v.end(); ++it) {       if (it != v.begin()) os <<  ,  ;       os << it->first <<   =   << it->second;     }     return os <<  ] ;   }   clock_t tStart = clock();   void faltu() { cerr <<   n ; }   template <typename T>   void faltu(T a[], int n) {     for (int i = 0; i < n; ++i) cerr << a[i] <<    ;     cerr <<   n ;   }   template <typename T, typename... hello>   void faltu(T arg, const hello &...rest) {     cerr << arg <<    ;     faltu(rest...);   }   const int mx = 1e5 + 5;   bool cnt[mx];   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     int n, k;     cin >> n >> k;     long long g;     cin >> g;     for (int i = 1; i < n; i++) {       long long x;       cin >> x;       g = gcd(x, g);     }     vector<long long> st;     for (long long i = 0, j = 0; i < k; i++, j += g) {       int z = j % k;       if (!cnt[z]) st.emplace_back(z), cnt[z] = 1;     }     cout << st.size() <<   n ;     for (int i = 0; i < k; i++) {       if (cnt[i]) cout << i <<    ;     }   }   