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;
bool comp(int a, int b) {
  if (a < b) return true;
  return false;
}
int val(int n) {
  if (n == 0) return 0;
  if (n == 5) return 5 * 5;
  if (n % 2 == 0) return 40;
  return 45;
}
int main() {
  int test;
  cin >> test;
  long long int n, m;
  vector<long long int> res(test);
  for (int t = 0; t < test; t++) {
    cin >> n >> m;
    long long int s = 0;
    if (n >= m) {
      long long int temp = m * 10;
      s += (n / temp) * val(m % 10);
      n = n % temp;
      for (long long int i = m; i <= n; i = i + m) {
        s += i % 10;
      }
    }
    res[t] = s;
  }
  for (int t = 0; t < test; t++) cout << res[t] << endl;
  return 0;
}
