func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     long long int ans = 1000000000000, n, m, i, d, j, a, fo = 0;     vector<long long int> v;     set<long long int> mset;     cin >> n >> m >> d;     for (i = 0; i < n; i++) {       for (j = 0; j < m; j++) {         cin >> a;         mset.insert(a);         v.emplace_back(a);       }     }     sort(v.begin(), v.end());     for (auto x : mset) {       long long int counter = 0;       for (j = 0; j < v.size(); j++) {         a = abs(x - v[j]);         if (a % d != 0 || counter >= ans) {           counter = 1000000000000;           break;         }         counter += (a / d);       }       if (ans > counter) {         ans = counter;       }     }     if (ans == 1000000000000)       cout <<  -1  << endl;     else       cout << ans << endl;   }   