1
class Solution {
2
 public:
3
  int minimumNumbers(int sum, int k) {
4
    if (sum == 0) return 0;
5
    for (int i = 1; i <= 10; ++i)
6
      if ((i * k) % 10 == sum % 10 && i * k <= sum) return i;
7
    return -1;
8
  }
9
};