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()) 
loi=[]
for k in range(t): 
    counter1=0  
    string1=list(input())

    placeholdern=''
    placeholderb=''
   
    for p in string1:

       
        if p!=" " and counter1==0:

            placeholdern=placeholdern+p
            

        elif p!=" " and counter1==1:

            placeholderb=placeholderb+p

        elif p==" ":
            counter1=counter1+1

    infotemplist=[]
    infotemplist.append(int(placeholdern))
    infotemplist.append(int(placeholderb))
    loi.append(infotemplist)

for k in range(t):
    n=loi[k][0]
    m=loi[k][1]
    req=0
    if m%2==0:
        if m%10==0:
            verywell=n//m
            a=verywell//10
            b=verywell%10
            req=a*0+sum([int(str(m*x)[-1]) for x in range(1,b+1)])
        else:
            verywell=n//m
            a=verywell//10
            b=verywell%10
            req=a*40+sum([int(str(m*x)[-1]) for x in range(1,b+1)])
    else:
        if m%5==0:
            verywell=n//m
            a=verywell//10
            b=verywell%10
            req=a*25+sum([int(str(m*x)[-1]) for x in range(1,b+1)])
        else:
            verywell=n//m
            a=verywell//10
            b=verywell%10
            req=a*45+sum([int(str(m*x)[-1]) for x in range(1,b+1)])

    print(req)
    
    
