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 java.util.*;
public class Main {
	static Scanner scan=new Scanner(System.in);
	static long [][]ar=new long[100][20];
	public static void init() {
		for(long i=1;i<=10;i++) {
			long tot=0;
			for(long j=1;j<=10;j++) {
				tot+=(i*j)%10;
				ar[(int) i][(int) j]=tot;
			}
			
			//System.out.println(tot);
			ar[(int) i][11]=tot;
		}
	}
	public static void main(String[] args) {
		int t=scan.nextInt();
		init();
		
		while(t>0) {
			t--;
			long n=scan.nextLong();
			long m=scan.nextLong();
			n/=m;
			int a=(int) (m%10);
			long ans = 0;
			long res=1;
			while(n>0) {
				long val=n%10;
				if(res==1)
				 ans += ar[a][(int) val];
				else ans+=ar[a][(int) 11]*(res/10)*val;
				 res*=10;
				 
				 //System.out.println("  ans =  "+ans+" n = "+n);
				n/=10;
			}
			System.out.println(ans);
			
			
		}
		
		
	}

}
