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
q = int(input())

for __ in range(q):
    n,m = [int(i) for i in input().split()]
    soma = 0
    count = n//m
    digitos = []
    numero = 0
    while True:
        numero += m
        digito = numero%10
        digitos.append(digito)
        if digito == 0:
            break
            
    vezes = count // len(digitos)
    resto = count%len(digitos)
    soma += vezes * sum(digitos)
    soma += sum(digitos[:resto])
    print(soma)
  		 			 	 	 	 		  	    	  		 	