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 n, m, b, k, maxi, s, h, f, c;
  cin >> n;
  vector<long long> a;
  k = 0;
  m = 0;
  for (int i = 0; i < n; ++i) {
    a.clear();
    s = 0;
    cin >> b >> k;
    f = b / k;
    s = 0;
    h = k;
    a.push_back(k % 10);
    while (k > 0) {
      s += k % 10;
      a.push_back((k + h) % 10);
      k = (k + h) % 10;
    }
    c = f / a.size() * s;
    for (int j = 0; j < f % a.size(); ++j) c += a[j];
    cout << c << endl;
  }
}
