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())
import math
while(t):
    n,m=map(int,input().split(" "))
    s=0
    if(m%2==0 and m%10!=0):
        x=m*5
        q=n//x
        s=s+(q*20)
        r=n%x
        q1=r//m
        while(q1>0):
            s1=(m*q1)%10
            s=s+s1
            q1-=1
        print(s)
    elif(m%2!=0 and m%5!=0):
        x=m*10
        q=n//x
        s=s+(q*45)
        r=n%x
        q1=r//m
        while(q1>0):
            s1=(m*q1)%10
            s=s+s1
            q1-=1
        print(s)
    elif(m%2==0 and m%10==0):
        print(0)
    else:
        d=n//m
        d=math.ceil(d/2)
        s=s+5*d
        print(s)
    
    t=t-1    