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;
void solve() {
  unsigned long long n, m;
  cin >> n >> m;
  int a[11];
  unsigned long long sum = 0, tsum = 0;
  for (int i = 1; i <= (10); ++i) {
    a[i] = ((m % 10) * i) % 10;
    sum += a[i];
  }
  unsigned long long div = n / m;
  unsigned long long rem = div % 10;
  tsum = sum * (div / 10);
  for (int i = 1; i <= rem; i++) tsum += a[i];
  cout << tsum << "\n";
}
int main() {
  std::ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t;
  t = 1;
  cin >> t;
  while (t--) {
    solve();
  }
  return 0;
}
