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;
string abc = "abcdefghijklmnopqrstuvwxyz";
int t, k;
string s;
char c;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  long long n, m;
  cin >> t;
  vector<long long> v[10];
  long long sum[10];
  sum[0] = 0;
  for (int i = 0; i < 10; i++) v[0].push_back(0);
  for (int i = 1; i <= 9; i++) {
    for (int j = i; j <= 10 * i; j += i) {
      v[i].push_back(j % 10);
    }
    if (i & 1)
      sum[i] = 45;
    else
      sum[i] = 40;
    if (i == 5) sum[i] = 25;
  }
  while (t--) {
    cin >> n >> m;
    long long divi = n / m;
    long long mul = divi / 10ll;
    long long mod = m % 10ll;
    long long dig = divi % 10ll;
    long long ans = mul * sum[mod];
    for (int i = 1; i <= dig; i++) {
      ans = ans + v[mod][i - 1];
    }
    cout << ans << '\n';
  }
}
