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
from sys import stdin
q=int(stdin.readline())
while(q>0):
    n,m=map(int,stdin.readline().split())
    
    
    divsum=0
    s=[]
    e=[0]*10
    x=m
    
    res=[]
    while(e[x%10]!=1):
        e[x%10]=1
        res.append(x%10)
        x+=m
    numterm=len(res)
    #print res
    if n>=m:
        sumtimes=(((n-m)/m)+1)/numterm
        
        rem=(((n-m)/m)+1)%numterm
        
        sumArray=sum(res)
        print sumtimes*sumArray + sum(res[0:rem])
    else:
        print "0"
        
    q-=1
    
    
