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
lista0 = [0,0,0,0,0,0,0,0,0,0]
lista1 = [1,2,3,4,5,6,7,8,9,0]
lista2 = [2,4,6,8,0,2,4,6,8,0]
lista3 = [3,6,9,2,5,8,1,4,7,0]
lista4 = [4,8,2,6,0,4,8,2,6,0]
lista5 = [5,0,5,0,5,0,5,0,5,0]
lista6 = [6,2,8,4,0,6,2,8,4,0]
lista7 = [7,4,1,8,5,2,9,6,3,0]
lista8 = [8,6,4,2,0,8,6,4,2,0]
lista9 = [9,8,7,6,5,4,3,2,1,0]

lista = [lista0,lista1,lista2,lista3,lista4,lista5,lista6,lista7,lista8,lista9]



casos = int(input())

for i in range(casos):
    n,m = [int(x) for x in input().split()]

    possibilidades = n//m
    sum = 0
    ultimoDigito = m%10



    for i in range(len(lista[ultimoDigito])):
        sum += lista[ultimoDigito][i]
    sum *= (possibilidades//10)

    for i in range(0,possibilidades%10):
        sum +=  lista[ultimoDigito][i%10]
    print(sum)

		  	 	    		 				  		 		 	  		