func_code_string: #include <bits/stdc++.h>   using namespace std;   bool isvowel(char c) {     c = tolower(c);     return (c ==  a  || c ==  e  || c ==  i  || c ==  o  || c ==  u );   }   long long gcd(long long a, long long b) {     if (b == 0) return a;     return gcd(b, a % b);   }   long long lcm(long long a, long long b) { return (a * b) / gcd(a, b); }   long long fastpow(long long base, long long p) {     if (p == 0) return 1;     long long num = fastpow(base, p / 2);     num *= num;     if (p % 2) num *= base;     return num;   }   int main() {     ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);     int n, m, x, q, ans = 0;     cin >> n >> m >> x;     string KeyBoard[n + 5], t;     map<char, bool> check;     vector<pair<int, int>> S;     for (int i = 1; i <= n; i++) {       cin >> KeyBoard[i];       for (int j = 0; j < m; j++) {         if (KeyBoard[i][j] ==  S ) S.push_back(make_pair(i, j + 1));       }     }     for (int i = 1; i <= n; i++) {       for (int j = 0; j < m; j++) {         if (KeyBoard[i][j] ==  S ) continue;         check[KeyBoard[i][j]] = true;         for (int k = 0; k < (int)S.size(); k++) {           if (sqrt(pow(i - S[k].first, 2) + pow(j - S[k].second + 1, 2)) <= x) {             check[toupper(KeyBoard[i][j])] = true;             break;           }         }       }     }     cin >> q >> t;     for (int i = 0; i < (int)t.size(); i++) {       if (!check[t[i]]) {         if (islower(t[i]) || !check[tolower(t[i])] || !S.size()) {           cout << -1;           return 0;         }         ans++;       }     }     cout << ans;     return 0;   }   