import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws IOException {
		int[] table = new int[101];
		for (int i=1;i<=100;i++) {
			table[i] = (table[i-1] + digit(i)) % 10;
		}
		
		Scanner in = new Scanner(new FileInputStream("cifra.in"));
		PrintWriter out = new PrintWriter("cifra.out");

		int t = in.nextInt();
		in.nextLine();
		
		for (int tc = 1; tc <= t; tc++) {
			String s = in.nextLine();
			int n = 0;
			int count = 1;
			for (int i=s.length()-1;i>=0 && i>=s.length()-2;i--) {
				n = n + (s.charAt(i)-'0')* count;
				count*=10;
			}
			
			out.println(table[n]);
		}

		in.close();
		out.close();
	}
	
	private static int digit(int n) {
		int[][] matrix = new int[][] {{0,0,0,0},
									  {1,1,1,1},
									  {6,2,4,8},
									  {1,3,9,7},
									  {6,4,6,4},
									  {5,5,5,5},
									  {6,6,6,6},
									  {1,7,9,3},
									  {6,8,4,2},
									  {1,9,1,9}};
		return matrix[n%10][n%4];
	}
}