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
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
for _ in range(int(input())):
    n=int(input())
    x=list(map(int,input().split()))
    m,k=map(int,input().split())
    
"""
qi=[]
for i in range(10):
    temp=[]
    for j in range(1,11):
        temp.append(int(str(i*j)[-1]))
    qi.append(temp)
for _ in range(int(input())):
    n,m=map(int,input().split())
    digit=int(str(m)[-1])
    div=n//m
    q=div//10
    r=div%10
    summ=sum(qi[digit])
    print(q*summ+sum(qi[digit][:r]))
    

                
    
  
                
            
                
        