func_code_string: #include <bits/stdc++.h>   using namespace std;   char a[55][55];   int n, m, x;   int dist(int p, int q, int r, int s) {     return (p - r) * (p - r) + (q - s) * (q - s);   }   int ok[128] = {}, appear[128] = {};   char s[1000000];   int main(void) {     scanf( %d%d%d , &n, &m, &x);     for (int i = 0; i < n; i++) scanf( %s , a[i]);     int S = 0;     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++)         if (a[i][j] ==  S ) {           S = 1;           for (int u = 0; u < n; u++)             for (int v = 0; v < m; v++)               if (dist(i, j, u, v) <= x * x) {                 ok[(int)a[u][v]] = 1;               }         } else           appear[(int)a[i][j]] = 1;     scanf( %d , &n);     scanf( %s , s);     int ans = 0, f = 0;     for (int i = 0; s[i]; i++)       if (s[i] >=  A  && s[i] <=  Z ) {         if (!S || !appear[s[i] + 32]) f = 1;         ans += !ok[s[i] + 32];       } else if (!appear[(int)s[i]])         f = 1;     if (f) ans = -1;     printf( %d n , ans);     return 0;   }   