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
import sys
#input=sys.stdin.readline
from collections import defaultdict as dc
from collections import Counter
from bisect import bisect_right, bisect_left
import math
for _ in range(int(input())):
    n,m=map(int,input().split())
    if n<m:
        print(0)
    else:
        l=[]
        i=m
        while(i<=10*m):
            l.append(i%10)
        #print(i)
            i+=m
    #print(l)
        for i in range(1,len(l)):
            l[i]=l[i]+l[i-1]
    #print(l)
        x=n//(10*m)
        c=l[-1]*x
        l.insert(0,0)
        if n>x*10*m:
            c+=l[(n-x*10*m)//m]
        print(c)