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() {
  long long a[100], n, m;
  int t, i, j, k;
  scanf("%d", &t);
  while (t--) {
    scanf("%lld %lld", &n, &m);
    for (i = 1; i <= 10; i++) {
      a[i] = (m * i) % 10;
    }
    long long x = (n / m);
    int b[100];
    b[0] = 0;
    for (i = 1; i <= 10; i++) {
      b[i] = b[i - 1] + a[i];
    }
    long long ans = 0;
    ans += (x / 10) * b[10] + b[x % 10];
    printf("%lld\n", ans);
  }
}
