Polycarp is reading a book consisting of n pages numbered from 1 to n. Every time he finishes the page with the number divisible by m, he writes down the last digit of this page number. For example, if n=15 and m=5, pages divisible by m are 5, 10, 15. Their last digits are 5, 0, 5 correspondingly, their sum is 10.

Your task is to calculate the sum of all digits Polycarp has written down.

You have to answer q independent queries.

Input

The first line of the input contains one integer q (1 ≤ q ≤ 1000) — the number of queries.

The following q lines contain queries, one per line. Each query is given as two integers n and m (1 ≤ n, m ≤ 10^{16}) — the number of pages in the book and required divisor, respectively.

Output

For each query print the answer for it — the sum of digits written down by Polycarp.

Example

Input


7
1 1
10 1
100 3
1024 14
998244353 1337
123 144
1234312817382646 13


Output


1
45
153
294
3359835
0
427262129093995
#include <bits/stdc++.h>
using namespace std;
int main() {
  int T;
  cin >> T;
  for (int t = 0; t < T; t++) {
    long long N, M, rip1, rip2, somma1 = 0, somma2 = 0, totale = 0;
    cin >> N >> M;
    if (N < M) {
      cout << 0 << endl;
    } else {
      rip1 = (N / M) / 10;
      rip2 = (N / M) % 10;
      vector<int> L;
      for (int l = 1; l <= 10; l++) {
        L.push_back((M * l) % 10);
        somma1 = somma1 + (M * l) % 10;
        if (l <= rip2) {
          somma2 = somma2 + L[l - 1];
        }
      }
      totale = (somma1 * rip1) + (somma2);
      cout << totale << endl;
    }
  }
  return 0;
}
