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
querries = int(input())

for i in range(querries):
    line = input().split()
    num_pages = int(line[0])
    m = int(line[1])

    num_divisors = num_pages // m
    last_digit = m % 10

    cicle = []
    multiplier = 1
    while not (last_digit * multiplier) % 10 in cicle:
        cicle.append((last_digit * multiplier) % 10)
        multiplier += 1
    sum_cicle = 0
    for digit in cicle:
        sum_cicle += digit
    
    total = sum_cicle * (num_divisors // len(cicle))
    for i in range(num_divisors % len(cicle)):
        total += cicle[i]
    print(total)
	 				   		 	  			     			