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
for i in range(int(input())):
    a = input()
    b = a.split()
    c = [int(d) for d in b]
    number_of_pages = c[0]
    divisor = c[1]
    last_digit_of_divisor = int(str(divisor)[-1])
    if last_digit_of_divisor == 1:
        l = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
    elif last_digit_of_divisor == 2:
        l = [2, 4, 6, 8, 0, 2, 4, 6, 8, 0]
    elif last_digit_of_divisor == 3:
        l = [3, 6, 9, 2, 5, 8, 1, 4, 7, 0]
    elif last_digit_of_divisor == 4:
        l = [4, 8, 2, 6, 0, 4, 8, 2, 6, 0]
    elif last_digit_of_divisor == 5:
        l = [5, 0, 5, 0, 5, 0, 5, 0, 5, 0]
    elif last_digit_of_divisor == 6:
        l = [6, 2, 8, 4, 0, 6, 2, 8, 4, 0]
    elif last_digit_of_divisor == 7:
        l = [7, 4, 1, 8, 5, 2, 9, 6, 3, 0]
    elif last_digit_of_divisor == 8:
        l = [8, 6, 4, 2, 0, 8, 6, 4, 2, 0]
    elif last_digit_of_divisor == 9:
        l = [9, 8, 7, 6, 5, 4 ,3, 2, 1, 0]
    elif last_digit_of_divisor == 0:
        l = [0, 0, 0, 0, 0, 0, 0, 0, 0 ,0]
        
    suml = ((number_of_pages//divisor)//10)*sum(l) 
    remaining =  ((number_of_pages//divisor)%10)
    sumn = sum(l[:remaining])
    print(suml + sumn)      