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
z=int(input())
for h in range(z):
    n,m=map(int,input().split())
    x = 0
    k = m
    y = n // m
    l = min(10, y)
    for i in range(l):
        if k >= 10:
            k = k % 10
        x += k
        k += m
    if y <= 10:
        print(x)
    else:
        q = y // 10
        if y >= 10:
            d = y % 10
        else:
            d = y
        sum = q * x
        k = m
        u = 0
        for i in range(d):
            if k >= 10:
                k = k % 10
            u += k
            k += m
        ans = sum + u
        print(ans)




