func_code_string: #include <bits/stdc++.h>   using namespace std;   long long tab[12], pr[12];   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int q;     cin >> q;     long long n, m, w, x;     for (int z = 0; z < q; z++) {       cin >> n >> m;       x = 1;       for (long long i = 1; i <= 11; i++) {         tab[i] = (tab[i - 1] + (m % 10)) % 10;         pr[i] = pr[i - 1] + tab[i];         if (tab[i] == tab[1] && i > 1) {           x = i - 1;           break;         }       }       w = pr[x] * (n / (x * m));       n %= x * m;       w += pr[n / m];       cout << w <<   n ;     }     return 0;   }   