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
# Paulo Pacitti
# 185447

def get_last_digits(m):
    i = 1
    digits = []
    while int(str(m*i)[-1]) != 0:
        digits.append(int(str(m*i)[-1]))
        i += 1
    digits.append(int(str(m*i)[-1]))
    return digits

def sum_last_digits(n, m, digits):
    s = 0
    s = ((n // m) // len(digits))*sum(digits)
    mod = (n // m) % len(digits)
    s += sum(digits[:mod])
    return s
    
q = int(input())
queries = []
result = []

for i in range(q):
    n, m = input().split(" ")
    queries.append([int(n), int(m)])

for i in range(q): 
    digits =  get_last_digits(queries[i][1])
    print(sum_last_digits(queries[i][0], queries[i][1], digits))
   	 	     					 	   	 			 	 	