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 q in range(Q):
    a=0
    n,m=map(int,input().split())
    t1=n//m
    if m%10==0:
        print(0)
    elif m%2==0:
        t2=t1//5*20
        t3=t1%5
        for i in range(1,t3+1):
            t2=t2+(i*(m%10)%10)
        print(t2)
    elif m%5==0:
        t2=t1//2*5
        t3=t1%2
        if t3==1:
            t2=t2+5
        print(t2)
    else:
        t2=t1//10*45
        t3=t1%10
        for i in range(1,t3+1):
            t2=t2+(i*(m%10)%10)
        print(t2)