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
prm = {1 : 10 , 2 : 5 , 3 : 10 , 4 : 5 , 5 : 2 , 6 : 5 , 7 : 10 , 8 : 5 , 9 : 10}
for case in range (int(input())) :
    N , K = input().split()
    N = int(N)
    K = int(K)

    a = N // K
    k = K % 10
    if (k > 0) :
        b = a // prm[k]
        c = a % prm[k]

        if (prm[k] == 5) :
            ans = b * 20
        elif (prm[k] == 10) :
            ans = b * 45
        elif (prm[k] == 2) :
            ans = b * 5
            
        for i in range (1 , c + 1) :
            ans += (i * k) % 10
    else :
        ans = 0
    print (ans)
    	    		 						 	  	    	