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
from pathlib import Path
import sys
import functools
import itertools
import re

def solve():
    # code goes here!!         
    for _ in range(int(input())):
        n,m = map(int,input().split())
        cnt = [0] * 10
        tot = n // m
#        if m * tot < n :
#            tot += 1
        for c in range(10):
            t = tot // 10
            cnt[c] += t
        for c in range((tot % 10) + 1):
            cnt[c] += 1
        ans = 0
        for c in range(10):
            ans += ((c * m) % 10) * cnt[c]
        print(ans)

def main():
    if Path('test.inp').exists():
        sys.stdin = open("test.inp","r")
    solve()

if __name__ == '__main__':
    main()


