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
t = int(input())

has = {1:45, 2: 40, 3:45, 4: 40, 5: 25, 6:40, 7: 45, 8: 40, 9: 45}

for _ in range(t):
    n, m = [int(x) for x in input().split()]
    
    k = n//m
    rec = k%10
    digit = m%10
    
    if digit == 0:
        print(0)
        continue
    
    k = k//10
    count = has[digit]*(k)
    
    i = 1
    while i <= rec:
        count += (digit*i)%10
        i += 1
        
    print(count)
    
    
    
    