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
n=int(input())
a=[]
for i in range(n):
    s=0
    a.append(list(map(int,input().split())))
    t =a[i][0]
    p= a[i][1]
    if t//p<10:
        for j in range(p,t+1,p):
            s+=j%10
    elif p%10 == 5:
        s=(t//p//10)*25
        for j in range(p, t//p%10*p+1,p):
            s+=j%10
    elif p%10==0:
        s=0
    elif  p%2==0:
        s=(t//p//10)*40
        for j in range(p, t//p%10*p+1,p):
            s+=j%10
    else:
         s=(t//p//10)*45
         for j in range(p, t//p%10*p+1,p):
            s+=j%10
    print(s)         
        
            
