func_code_string: #include <bits/stdc++.h>   int main() {     long long int n, m, i, ans = 0, cish, h, sd = 0, c;     int q, j;     scanf( %d , &q);     int a[10][10] = {{0},                      {1, 2, 3, 4, 5, 6, 7, 8, 9, 0},                      {2, 4, 6, 8, 0},                      {3, 6, 9, 2, 5, 8, 1, 4, 7, 0},                      {4, 8, 2, 6, 0},                      {5, 0},                      {6, 2, 8, 4, 0},                      {7, 4, 1, 8, 5, 2, 9, 6, 3, 0},                      {8, 6, 4, 2, 0},                      {9, 8, 7, 6, 5, 4, 3, 2, 1, 0}};     for (j = 0; j < q; j++) {       scanf( %lld%lld , &n, &m);       c = m % 10;       switch (c) {         case 1:         case 3:         case 7:         case 9:           cish = 10;           h = 45;           break;         case 2:         case 4:         case 6:         case 8:           cish = 5;           h = 20;           break;         case 5:           cish = 2;           h = 5;           break;         case 0:           cish = 1;           h = 0;           break;       }       int y;       for (y = 0; y < (n / m) % cish; y++) sd += a[c][y];       ans = (n / m) / cish * h + sd;       printf( %lld n , ans);       ans = 0;       sd = 0;     }     return 0;   }   