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 {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		
		int[][] digit = new int[10][11];
		int[] num = new int[10];
		int[] sum = new int[10];
		for(int i=0;i<10;i++) {
			count(i, digit, num, sum);
		}
		/*for(int i=0;i<10;i++) {
			System.out.printf("%d\n", i);
			for(int j=0;j<11;j++) {
				System.out.print(digit[i][j]+" ");
			}
			System.out.printf("\n%d %d\n", num[i], sum[i]);
		}*/
		
		int q = sc.nextInt();
		while(q-->0) {
			long n = sc.nextLong();
			long m = sc.nextLong();
			
			int k = (int)(m%10);
			long d = n/m;
			long Sum = 0;
			for(int i=1;i<=(int)(d%num[k]);i++) {
				Sum+=digit[k][i];
			}
			Sum = Sum+d/num[k]*sum[k];
			System.out.println(Sum);
		}
	}
	static void count(int n, int[][] digit, int[] num, int[] sum) {
		int a = n, i=1, c = 0, Sum = 0;
		while(true) {
			a%=10;
			digit[n][i++] = a;
			Sum+=a;
			c++;
			if(a==0)
				break;
			a+=n;
		}
		num[n] = c;
		sum[n] = Sum;
	}
}