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 collections import defaultdict as DD
from bisect import bisect_left as BL
from bisect import bisect_right as BR
from itertools import combinations as IC
from itertools import permutations as IP
from random import randint as RI
import sys
MOD=pow(10,9)+7

def IN(f=0):
    if f==0:
        return ( [int(i) for i in sys.stdin.readline().split()] )
    else:
        return ( int(sys.stdin.readline()) )
tc=int(input())

for _ in range(tc):
    n,m=IN()
    a=[]
    p=int(str(m)[-1])
    for i in range(1,11):
        a.append(int(str(i*p)[-1]))
    #print(a)
    n=n//m
    f=n//10
    ans=sum(a)*f
    ans+=sum(a[:n%10])
    print(ans)
        
