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 int t, n, i, s, a1, b1, m;
  cin >> t;
  while (t--) {
    cin >> n >> m;
    if (n < m) {
      cout << "0\n";
      continue;
    }
    if (n == m)
      cout << n % 10 << "\n";
    else {
      long long int a[10] = {}, b[11] = {};
      for (i = 1; i <= 10; i++) {
        a[i - 1] = (m * i) % 10;
        b[i] += a[i - 1] + b[i - 1];
      }
      a1 = n / m;
      b1 = a1 % 10;
      a1 = a1 / 10;
      s = a1 * b[10] + b[b1];
      cout << s << "\n";
    }
  }
  return 0;
}
