#include<fstream>
//#include<math.h>
using namespace std;
const int t[]={1,5,2,8,3,9,2,8,7,7,8,4,7,3,8,4,1,5,4,4};
int main()
{
	ifstream f("cifra.in");
	ofstream g("cifra.out");
	char s[102]="";
	int r[101]={1,5,2,8,3,9,2,8,7,7,8,4,7,3,8,4,1,5,4,4};
	for(int i=20;i<100;i++)
	
		r[i]=(t[i%20]+4*(i/20))%10;
		//g<<r[i]<<" ";
	/*for(int i=0;i<100;i++)
		g<<r[i]<<" ";*/
	/*int p;
	f>>p;
	while(!f.eof())
	{
		f>>s;
		/*if(strlen(s)<3) 
		{
			char i[6]="00";
			strcat(i,s);
			strcpy(s,i);
		}*/
		/*if(strlen(s)>3){//int u=strlen(s)-3;
		strcpy(s,s+strlen(s)-3);}*/
		
		//g<<s<<endl;
		/*int /*k=(int)s[0]-48,*//*n=(int)s[strlen(s)-2]-48,m=(int)s[strlen(s)-1]-48;
		//g<<k<<" "<<n<<" "<<m<<endl;
		/*if(k<0||k>9) k=0;*/
		/*if(n<0||n>9) n=0;
		n=n*10+m;
		//k=k*10+n;
		//g<<k<<" ";
		/*nr=(/*(k*20)+*//*(n/20)*4+t[n%20-1])%10;
		//g<<(k%200)<<" "<<nr<<" ";
		//g<<t[0]<<endl;
		
		//nr=(nr+t[(n%20)-1])%10;
		//g<<n<<" "<<t[(n%20)-1]<<" "<<nr<<" ";
		*/
		/*g<<r[n-1]<<endl;
	}
	*/
	return 0;
}