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;
long long sum1(long long n, long long m) {
  long long sum = 0;
  long long z = n % 10;
  long long i;
  for (i = 1; i <= m; i++) {
    sum += (z * i) % 10;
  }
  return sum;
}
int main() {
  long long t;
  cin >> t;
  map<long long, long long> m1;
  m1[1] = 45;
  m1[2] = 40;
  m1[3] = 45;
  m1[4] = 40;
  m1[5] = 25;
  m1[6] = 40;
  m1[7] = 45;
  m1[8] = 40;
  m1[9] = 45;
  m1[0] = 0;
  while (t--) {
    long long x, y;
    cin >> x >> y;
    long long z = (x / y);
    long long z1 = z % 10;
    if (y % 10 == 0) {
      cout << 0 << endl;
      continue;
    }
    long long z2 = z / 10;
    long long sum2 = 0;
    sum2 += z2 * m1[y % 10];
    sum2 += sum1(y, z1);
    cout << sum2 << endl;
  }
}
