/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner dane = new Scanner(System.in);
 
		int a = dane.nextInt();
 
 
		for(int i = 0; i < a; i++)
		{
			int podstawa = dane.nextInt();
			int wykladnik  = dane.nextInt();
 
			System.out.println(jednosc(podstawa,wykladnik));
 
		}
	}
 
		public static long jednosc(int a, int b)
	{
	long p = 1;
	if (b ==0)
	    return 1;
	b = b % 4;
 
	if (b == 0) b = 4;
	for (int i = 0; i < b; ++i){
	  p *= a;
	/// dodałem, abyś widział co się dzieje
	///
	 System.out.println(p); 
	///
	///
	}
 
	return p%10 ;
}
 
}

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6
13 4
1000000000 1
1000000000 2
1000000000 3
1000000000 4
1000000000 1000000000