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;
  long long int n, m, xxx, yyy, zzz, ans = 0;
  for (int z = 0; z < t; z++) {
    ans = 0;
    cin >> n >> m;
    xxx = n / m;
    if (m < n) {
      if (xxx <= 10) {
        for (long long int x = m; x <= n; x += m) {
          yyy = x % 10;
          ans += yyy;
        }
        cout << ans << endl;
      } else {
        for (long long int x = m; x <= 10 * m; x += m) {
          yyy = x % 10;
          ans += yyy;
        }
        yyy = xxx / 10;
        ans *= yyy;
        xxx = xxx % 10;
        for (long long int x = m; x <= xxx * m; x += m) {
          yyy = x % 10;
          ans += yyy;
        }
        cout << ans << endl;
      }
    } else if (n == m) {
      xxx = n % 10;
      cout << xxx << endl;
    } else {
      cout << 0 << endl;
    }
  }
}
