#include <stdio.h>
#include <math.h>
int main()
{
	int s,i,suma = 0;
	freopen("cifra.in", "r", stdin);
	freopen("cifra.out", "w", stdout);

	scanf("%s",&s);
	
	while(s!=NULL){
	i = s % 10;
	suma = pow(i,i);
	}

	printf("%d", suma % 10);
 	
	return 0;
}