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
q = int(input())
for _ in range(q):
    n, m = map(int, input().split())
    k = m % 10
    ans = 0
    
    if k == 1 or k == 3 or k == 7 or k == 9:
        ans = ((n // m) // 10) * 45
        t = (n // m) % 10
        q = k
        for _ in range(t):
            ans += q % 10
            q += k
            
    elif k == 2 or k == 4 or k == 6 or k == 8:
        ans = ((n // m) // 5) * 20
        t = (n // m) % 5
        q = k
        for _ in range(t):
            ans += q % 10
            q += k
            
    elif k == 5:
        ans = ((n // m + 1) // 2) * 5
        
    elif k == 0:
        ans = 0
    print(ans)