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 testcases = 1, n, m, sum, no, rem;
  int arr[11];
  cin >> testcases;
  while (testcases--) {
    cin >> n >> m;
    arr[1] = sum = m % 10;
    arr[10] = 0;
    for (int i = 2; i < 10; i++) {
      arr[i] = (m * i) % 10;
      sum += arr[i];
    }
    no = n / (m * 10);
    sum = sum * no;
    rem = (n / m - no * 10);
    for (int i = 1; i <= rem; i++) {
      sum += arr[i];
    }
    cout << sum << endl;
  }
  return 0;
}
