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() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long a[10][11];
  long long sum[10][11];
  memset(sum, 0, sizeof(sum));
  for (long long i = 1; i <= 9; i++) {
    a[i][0] = 0;
    sum[i][0] = 0;
  }
  for (long long i = 1; i <= 9; i++) {
    long long sum1 = 0;
    for (long long j = 1; j <= 9; j++) {
      a[i][j] = (a[i][j - 1] + i) % 10;
      sum1 += a[i][j];
      sum[i][j] = sum[i][j - 1] + a[i][j];
    }
    a[i][10] = sum1;
  }
  long long t;
  cin >> t;
  while (t--) {
    long long m, n;
    cin >> n >> m;
    long long x = n / m;
    long long y = m % 10;
    long long z = n % m;
    long long r = x / 10;
    long long h = x % 10;
    unsigned long long ans = r * sum[y][9] + sum[y][h];
    cout << ans << '\n';
  }
}
