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

using namespace std;

int main()
{
	int i, a=0, v[101];
	char s[101], p[2];
	
	FILE *f, *g;
	
	f = fopen("cifra.in", "r");
	g = fopen("cifra.out", "w");
	
	for (i=1; i<=100;i++)
	{
		if (i%10 == 1)
			a += 1;
		if (i%10 == 2)
			a += 4;
		if (i%10 == 3)
			a += 7;
		if (i%10 == 4)
			a += 6;
		if (i%10 == 5)
			a += 5;
		if (i%10 == 6)
			a += 6;
		if (i%10 == 7)
			a += 3;
		if (i%10 == 8)
			a += 6;
		if (i%10 == 9)
			a += 9;
		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;
}