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
sums=[0]*11
table=[]
table.append(0)
for i in range(1,10):
    x=[]
    sumi=0
    x.append(0)
    for j in range(1,10):
        x.append((i*j)%10)
        sumi+=(i*j)%10
    table.append(x)
    sums[i]=sumi

T=int(input())
while T>0:    
    a,b=map(int,input().split())
    ans=(a//(b*10))*sums[b%10]
    mod=a%(b*10)
    i=1
    if b%10!=0:
        while(i*b)<=mod:
            ans+=table[b%10][i]
            i+=1
    print(ans)
    T=T-1 
    


