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() {
  unsigned long long int n, t, m, x, y, i, z, b, s = 0;
  scanf("%llu", &t);
  while (t--) {
    scanf("%llu %llu", &n, &m);
    x = n / m;
    y = x % 10;
    if (n < m)
      printf("%d\n", 0);
    else if (n == m)
      printf("%llu\n", m % 10);
    else {
      for (i = 1; i <= 9; i++) {
        z = m * i;
        z = z % 10;
        s = s + z;
        if (i == y) b = s;
      }
      if (y == 0) b = 0;
      x = x / 10;
      s = s * x + b;
      printf("%llu\n", s);
      s = 0;
    }
  }
  return 0;
}
