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>
int main() {
  int q, i, a[10000];
  long long int n, m, sum, x, d, l, k, xh, ge;
  while (~scanf("%d", &q)) {
    while (q--) {
      memset(a, 0, sizeof(a));
      sum = 0;
      scanf("%lld %lld", &n, &m);
      ge = m % 10;
      for (i = 0, d = m; i < 10; i++, d += m) {
        a[i] = d % 10;
        sum += a[i];
      }
      l = n / (m * 10);
      k = l * sum;
      xh = (n - l * m * 10) / m;
      for (i = 0; i < xh; i++) k += a[i];
      printf("%lld\n", k);
    }
  }
}
