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;
const int inf = 0x3f3f3f3f;
const int maxn = 200100;
inline long long read() {
  long long date = 0, w = 1;
  char c = 0;
  while (c < '0' || c > '9') {
    if (c == '-') w = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    date = date * 10 + c - '0';
    c = getchar();
  }
  return date * w;
}
inline void print(long long x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  if (x > 9) print(x / 10);
  putchar(x % 10 + '0');
}
long long a[20] = {0, 45, 40, 45, 40, 25, 40, 45, 40, 45};
int main() {
  long long n, m;
  int t;
  scanf("%d", &t);
  while (t--) {
    n = read(), m = read();
    n = n / m;
    m = m % 10;
    long long ans = 0;
    if (n) {
      ans = a[m] * (n / 10);
      n = n % 10;
      for (int i = 1; i <= n; i++) {
        ans += (m * i) % 10;
      }
      print(ans);
      puts("");
    } else
      puts("0");
  }
  return 0;
}
