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 Counter
#q=input()
for q in range(input()):
    n,m=map(int,raw_input().split())
    d=Counter()
    sm=0
    for i in range(1,10):
        d[i]+=int(str(i*m)[-1])
        sm+=int(str(i*m)[-1])
    
    ans=sm*(n/(m*10))
    
    x=n%(m*10)
    x/=m
    #print n,m,ans,x
    
    for i in range(1,x+1):
        ans+=d[i]
    print ans
    
