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 sys import stdin
t=int(stdin.readline().strip())
for j in range(t):
    n,m=map(int,stdin.readline().strip().split())
    vis=[False for i in range(10)]
    x=m%10
    s=[]
    while vis[x]!=True:
        vis[x]=True
        s.append(x)
        x=(x+m)%10
    y=n//m
    ans=0
    z=(y//len(s))*len(s)
    ans+=sum(s)*(y//len(s))
    d=y-z
    for i in range(d):
        ans+=s[i]
    print(ans)
    
    
    
    
        
            
    
