#include<fstream>
#include<stdio.h>
#include<string.h>
#include<stdlib.h>

using namespace std;

int main()
{
	int i, a=0, v[101],b,j;
	char s[101], p[101];
	
	FILE *f, *g;
	
	f = fopen("cifra.in", "r");
	g = fopen("cifra.out", "w");

	for (i=1; i<=100;i++)
	{
		if (i%10 == 1 && i<10)
			a += 1;
		if (i%10 == 2 && i<10)
			a += 4;
		if (i%10 == 3 && i<10)
			a += 7;
		if (i%10 == 4 && i<10)
			a += 6;
		if (i%10 == 5 && i<10)
			a += 5;
		if (i%10 == 6 && i<10)
			a += 6;
		if (i%10 == 7 && i<10)
			a += 3;
		if (i%10 == 8 && i<10)
			a += 6;
		if (i%10 == 9 && i<10)
			a += 9;
			
		if (i>10)
		{
			b = i%10;
			for (j=2;j<=i;j++)	
				b = (b * i)%10;
			a += b;		
		}
		
				
		if (a>=10) 
			a = a%10;
		v[i]=a;
	}
	
	fscanf(f, "%s", &s);
	if (strlen(s)>2)
		strcpy(p, s + (strlen(s)-2));
	else
		strcpy(p, s);
	a = atoi(p);
	fprintf(g, "%d", v[a]);
	

	return 0;
}