func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long n, step, smallest, count = 0;     bool possible = true;     cin >> n >> step;     vector<long long> p(n);     cin >> p[0];     smallest = p[0];     for (int i = 1; i < n; i++) {       cin >> p[i];       if (p[i] < smallest) {         smallest = p[i];       }     }     for (int i = 0; i < n; i++) {       if ((p[i] - smallest) % step != 0) {         cout << -1 << endl;         possible = false;         break;       } else {         count += (p[i] - smallest) / step;       }     }     if (possible == true) {       cout << count << endl;     }     return 0;   }   