import java.math.BigInteger;
import java.util.Scanner;


 
public class Main {
    
    public static void main(String[] args) {
        BigInteger [] b = new BigInteger[7200];
        b[1]=b[2]=b[3]=b[4]= BigInteger.valueOf(1);
        int len = 0;
        for(int i=5;i<7200;i++){
            b[i] = b[i-1].add(b[i-2]).add(b[i-3]).add(b[i-4]);
        }
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            int n = sc.nextInt();
            System.out.println(b[n]);
        }
    }
}