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())
for x in range(t):
    # n=input()
    a=list(map(int,input().split(" ")))
    b=a[0]
    c=a[1]
    d=b//c
    if d>10:
        nl=0
        m=c
        arr=[]
        while(nl<10):
            arr.append(m%10)
            m+=c
            nl+=1
        div=d//10
        rem=d%10
        ans=div*sum(arr)
        ans+=sum(arr[:rem])
    else:
        m=c
        arr=[]
        while(d!=0):
            arr.append(m%10)
            m+=c
            d-=1
        ans=sum(arr)
    print(ans)