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
t = int(input())
for _ in range(t):
    n, m = map(int, input().split())

    ans = 0

    if m == 1:
        if n == 1:
            ans = 1
        else:
            ans = 45 * (n // 10)
            if n % 10 != 0:
                for i in range(1, n % 10 + 1):
                    ans += i
    elif (m > n) or (m == 10):
        ans = 0
    else:
        if (m % 2 == 1):
            k = 10
        else:
            k = 5
        for i in range(k):
            g = (i + 1) * m
            g %= 10
            ans += g * (n // (m * k))
            #print(g, ans, 'qwerqwer')
        for i in range(m, n % (m * k) + 1, m):
            ans += i % 10
            #print(ans, i + 1 * m, i)
    print(ans)
