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;
int32_t main() {
  long long t;
  cin >> t;
  while (t--) {
    long long n, m;
    cin >> n >> m;
    long long a, b, c, d;
    long long sum = 0;
    if (m % 10 == 0 || m > n) {
      cout << 0 << endl;
    } else {
      if ((m % 10) % 2 == 0) {
        n /= m;
        a = n / 10;
        sum += a * 40;
        b = n % 10;
        c = m % 10;
        for (long long i = 1; i <= b; i++) {
          d = c * i;
          sum += d % 10;
        }
        cout << sum << endl;
      } else if ((m % 10) % 3 == 0 || m % 10 == 7 || m % 10 == 1) {
        n /= m;
        a = n / 10;
        sum += a * 45;
        b = n % 10;
        c = m % 10;
        for (long long i = 1; i <= b; i++) {
          d = c * i;
          sum += d % 10;
        }
        cout << sum << endl;
      } else if (m % 10 == 5) {
        n /= m;
        a = n / 10;
        sum += a * 25;
        b = n % 10;
        c = m % 10;
        for (long long i = 1; i <= b; i++) {
          d = c * i;
          sum += d % 10;
        }
        cout << sum << endl;
      }
    }
  }
}
