func_code_string: #include <bits/stdc++.h>   using namespace std;   int r[305];   int main() {     int p, n;     cin >> p >> n;     int a[n + 5];     for (int i = 1; i <= n; i++) {       cin >> a[i];     }     int sum = 0, c = 0, f = -1;     for (int i = 1; i <= n; i++) {       c = a[i] % p;       if (r[c] == 0) {         f = -1;         r[c]++;       } else {         f = i;         break;       }     }     cout << f << endl;     return 0;   }   