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())
mod = pow(10,9) + 7
for y in range(t):
    n,m = map(int,input().split())
    u = n//m
    v = m%10
    c = 0
    if(n < m):
    	print(0)
    else:
        if v == 0:
    	    c = 0
        elif m % 2 == 0:
            c = (40*(u//10))
        elif(v == 5):
            c = (25*(u//10))
        else:
            c = (45*(u//10))
	    #print(c)
        for i in range(u%10):
            c += (v*(i+1))%10
        print(c)