#include<fstream>
#include<iostream>
#include<string.h>

using namespace std;

int main()
{
	int i, a=0, v[101];
	char s[101], *p;
	
	ifstream f ("cifra.in");
	ofstream g ("cifra.out");
	
	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;
	}
	
	f>>s;
	if (strlen(s)>2)
		strcpy (p, s + (strlen(s)-2));
	else
		strcpy(p,s);
	a = atoi(p);
	g<<v[a];
	
	f.close();
	g.close();
	return 0;
}