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
# TAIWAN NUMBER ONE!!!!!!!!!!!!!!!!!!!
# TAIWAN NUMBER ONE!!!!!!!!!!!!!!!!!!!
# TAIWAN NUMBER ONE!!!!!!!!!!!!!!!!!!!
from sys import stdin, stdout
from collections import defaultdict
from collections import deque
import math
import copy
 
T = int(input())
#N = int(input())
#s1 = input()
#s2 = input()
#N,Q = [int(x) for x in stdin.readline().split()]
#arr = [int(x) for x in stdin.readline().split()]

for i in range(T):
    N,M = [int(x) for x in stdin.readline().split()]
    
    d = M%10
    
    q = N//M
    
    tail = []
    
    t = 0
    while True:
        t = (t + d)%10
        if t not in tail:
            tail.append(t)
        else:
            break
            
    L = len(tail)
    
    s = sum(tail)
    q2 = q//L
    r = q%L
    
    #print(q2,r)
    print(q2*s+sum(tail[:r]))