func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 5.2e3 + 5;   int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }   char s[MAXN];   bool a[MAXN][MAXN];   int main(void) {     int n;     scanf( %d , &n);     for (int i = 1; i <= n; ++i) {       scanf( %s , s + 1);       for (int j = 1; s[j]; ++j) {         if (s[j] >=  0  && s[j] <=  9 )           s[j] -=  0 ;         else           s[j] = s[j] -  A  + 10;         for (int k = 0; k < 4; ++k) a[i][(j << 2) - k] = (s[j] >> k) & 1;       }     }     int x = 0;     for (int i = 1; i <= n && x != 1; ++i)       for (int l = 1, r = 1; l <= n && x != 1; l = r) {         while (r <= n && a[i][r] == a[i][l]) ++r;         x = gcd(x, r - l);       }     for (int j = 1; j <= n && x != 1; ++j)       for (int l = 1, r = 1; l <= n && x != 1; l = r) {         while (r <= n && a[r][j] == a[l][j]) ++r;         x = gcd(x, r - l);       }     printf( %d , x);     return 0;   }   