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())
while q:
    n,m=map(int,input().split())
    m=str(m)
    a=m[len(m)-1]
    m=int(m)
    if(a=="0"):
        ans=0
    elif(a=="1"):
        b=[1,2,3,4,5,6,7,8,9,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1
    elif(a=="2"):
        b=[2,4,6,8,0,2,4,6,8,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1
    elif(a=="3"):
        b=[3,6,9,2,5,8,1,4,7,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1  
    elif(a=="4"):
        b=[4,8,2,6,0,4,8,2,6,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1     
    elif(a=="5"):
        b=[5,0,5,0,5,0,5,0,5,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1       
    elif(a=="6"):
        b=[6,2,8,4,0,6,2,8,4,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1  
    elif(a=="7"):
        b=[7,4,1,8,5,2,9,6,3,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1  
    elif(a=="8"):
        b=[8,6,4,2,0,8,6,4,2,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1   
    else:
        b=[9,8,7,6,5,4,3,2,1,0]
        ans=((n//m)//10)*sum(b)
        c=(n//m)-((n//m)//10)*10
        d=0
        while c:
            ans+=b[d]
            d+=1
            c-=1    
    print(ans)
    q-=1
        