#include <stdio.h>
#include <math.h>
int ultima(int n)
{
	return n%10;
}
int suma(int n)
{
	int i;
	int s;
	s=0;
	for (i=1;i<=n;i++){
	s=s+pow(i,i);
	}
	return s;
}
int main()
{
	int i,n;
	char x[100000000];
	
	freopen("cifra.in","r",stdin);
	freopen("cifra.out","w",stdout);
	scanf("%d",&n);
	scanf("%s",&x);
	for (i=1;i<strlen(n);i++)
		printf("%s", ultima(x[i]));
	return 0;




	/*for (i=1;i<=n;i++){
		scanf("%s",&x);
	printf("%d\n", ultima(suma(x)));*/
	/*for (i=1;i<strlen(x);i++)
		x[i]=
	printf("%d", ultima(x[n-1]));
	return 0;*/
}