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() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int q;
  cin >> q;
  while (q--) {
    uint64_t n, m;
    cin >> n >> m;
    uint64_t ans;
    if (m % 10 == 0) {
      cout << 0 << '\n';
      continue;
    }
    if (m % 5 == 0) {
      ans = (n / m) / 10 * 25;
    } else if (m % 2) {
      ans = (n / m) / 10 * 45;
    } else {
      ans = (n / m) / 10 * 40;
    }
    for (int i = 1; i <= (n - m * ((n / m) / 10 * 10)) / m; i++) {
      ans += ((m % 10) * i) % 10;
    }
    cout << ans << '\n';
  }
}
