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;
set<long long int> dgt;
int dgts[100] = {0};
void init() {
  dgt.clear();
  memset(dgts, 0, sizeof(dgts));
}
void solve() {
  long long int n, m;
  scanf("%lld %lld", &n, &m);
  long long int t = m % 10;
  long long int sum = 0;
  int count = 0;
  while (dgt.find(t % 10) == dgt.end()) {
    count++;
    dgts[count] = dgts[count - 1] + t;
    sum += t;
    dgt.insert(t % 10);
    t = (t + m) % 10;
  }
  printf("%lld\n", sum * ((n / m) / count) + dgts[(n / m) % count]);
}
int main() {
  int n;
  scanf("%d", &n);
  while (n--) {
    init();
    solve();
  }
  return 0;
}
