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
a = {0: [0],
     1: [1, 2, 3, 4, 5, 6, 7, 8, 9, 0],
     2: [2, 4, 6, 8, 0],
     3: [3, 6, 9, 2, 5, 8, 1, 4, 7, 0],
     4: [4, 8, 2, 6, 0],
     5: [5, 0],
     6: [6, 2, 8, 4, 0],
     7: [7, 4, 1, 8, 5, 2, 9, 6, 3, 0],
     8: [8, 6, 4, 2, 0],
     9: [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
}

q = int(input())
for i in range(q):
    n, m = map(int, input().split())
    ans = 0
    l = n // m
    m = int(str(m)[-1])
    cel = l // len(a[m])
    for elem in a[m]:
        ans += elem * cel
    ost = l % len(a[m])
    for j in range(ost):
        ans += a[m][j]
    print(ans)
