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())

tenlist=[pow(10,i) for i in range(20)]

def get(u):
    sum=0
    kk=u
    for i in range(10):
        sum+=int(str(kk)[-1])
        kk+=u
    return sum          #得到10个分数的尾和

for i in range(q):
    n,m=input().split()
    n=int(n)
    m=int(m)
    div=n//m
    wsum=get(m)
    sum=0
    k= len(str(div))-2
    for c in str(div):
        if k<0: break
        sum+=int(c)*tenlist[k]*wsum
        k-=1
    for k in range(int(str(div)[-1])):
        sum+=int(str(m*(k+1))[-1])
    print(sum)