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 collections import deque
import sys

def inp():
    return sys.stdin.readline().strip()
for _ in range(int(inp())):
    n,m=map(int,inp().split())
    cycle=[]
    s=set()
    start=1
    while (start*m)%m not in s:
        val=(start*m)%10
        s.add(val)
        cycle.append(val)
        start+=1 
    q=n//m 
    r=q%len(cycle)
    ct=(q//(len(cycle)))*sum(cycle)+sum(cycle[:r])
    print(ct)