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;
double const EPS = 1e-8, PI = acos(-1);
const int N = 2e5 + 9, M = 50, OO = 1e9 + 9, MOD = 1e9 + 7;
long long cum[11];
int main() {
  cout << fixed << setprecision(0), ios::sync_with_stdio(false),
      cin.tie(nullptr), cout.tie(nullptr);
  int t;
  cin >> t;
  while (t--) {
    long long n, m;
    cin >> n >> m;
    for (int i = 1; i <= 10; ++i) {
      cum[i] = cum[i - 1] + (m * i) % 10;
    }
    n /= m;
    long long cyc = n / 10;
    long long rem = n % 10;
    cout << cum[10] * cyc + cum[rem] << '\n';
  }
  return 0;
}
