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
n = int(input())
for qqq in range(n):
    s = input().split(' ')
    st = int(s[0])
    m = int(s[1])
    if m %10 == 0:
        print(0)
    else:
        if int(s[1][-1]) == 1:
            mas = [1,2,3,4,5,6,7,8,9,0]
        elif int(s[1][-1]) == 2:
            mas = [2,4,6,8,0,2,4,6,8,0]
        elif int(s[1][-1]) == 3:
            mas = [3,6,9,2,5,8,1,4,7,0]
        elif int(s[1][-1]) == 4:
            mas = [4,8,2,6,0,4,8,2,6,0]
        elif int(s[1][-1]) == 5:
            mas = [5,0,5,0,5,0,5,0,5,0]
        elif int(s[1][-1]) == 6:
            mas = [6,2,8,4,0,6,2,8,4,0]
        elif int(s[1][-1]) == 7:
            mas = [7,4,1,8,5,2,9,6,3,0]
        elif int(s[1][-1]) == 8:
            mas = [8,6,4,2,0,8,6,4,2,0]
        elif int(s[1][-1]) == 9:
            mas = [9,8,7,6,5,4,3,2,1,0]
        summa = sum(mas)
        tt = st//m
        print(tt//10*summa + sum(mas[:tt%10]))