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
qtd = int(input())
for i in range(0, qtd):
    numerodepaginas, divisor = list(map(int, input().split()))
    divisao = int(numerodepaginas/(divisor*10))
    ultimodigito = divisor%10
    if ultimodigito in [1,3,5,7,9]:
        numeromagico = 45
    if ultimodigito in [2,4,6,8]:
        numeromagico = 40
    if ultimodigito == 5:
        numeromagico = 25
    if ultimodigito == 0:
        numeromagico = 0
    totalparcial = numeromagico*divisao
    resto = numerodepaginas - (divisao*10*divisor)
    for i in range(divisor, resto+1, divisor):
         totalparcial += i  % 10


    print(totalparcial)


#ultimo digito = 1: 45 a cada 10
#ultimo digito = 2: 40 a cada 10
#ultimo digito = 3: 45 a cada 10
#...
#numeros 1, 3, 5, 7, 9: soma 45 a cada 10
#numeros 2, 4, 6, 8: soma 40 a cada 10
#numero 5: 25 a cada 10


#dividir um pelo outro
#pegar até o penultimo digito
#ultimo digito usar for
	 	 				  			  			 		 			  				