import java.math.BigInteger;
import java.util.Scanner;
public class main{
	static Scanner sc=new Scanner(System.in);
	public static void main(String args[]){
		int n=sc.nextInt();
		long[][] A={
				{1,3},
				{1,1}
		};
		A=MtPow(n,A);
		long a=A[0][0];
		if(n%2==0){
			System.out.print((2*a-1)%1000);
		}else{
			System.out.print((2*a)%1000);
		}
	}

//int matrix^matrix(becareful about the size)
public static long[][] MtPrd(long[][] A,long[][] B){
	long[][] C=new long[A.length][B[0].length];
	for(int i=0;i<A.length;i++){
		for(int j=0;j<B[0].length;j++){
			for(int k=0;k<B[0].length;k++){
				C[i][j]+=A[i][k]*B[k][j];
				C[i][j]%=1000;
			}
		}
	}
	return C;
}
//A+B
public static long[][] MtSum(long[][] A,long[][] B){
	long[][] C=new long[A[0].length][A.length];
	for(int i=0;i<A.length;i++){
		for(int j=0;j<A[0].length;j++){
			C[i][j]=A[i][j]+B[i][j];
		}
	}
	return C;
}
//convert to binary
public static BigInteger bi(int n){
	BigInteger b=new BigInteger("0");
	BigInteger digit=new BigInteger("10");
	for(int i=0;n!=0;i++){
		//System.out.println("n="+n+"\nb="+b);
		if(n%2==0){
			n/=2;
		}else{
			n-=1;
			n/=2;
			b=b.add(digit.pow(i));
		}
	}
	return b;
}

//R=A^n
public static long[][] MtPow(int n,long[][] A){
	BigInteger b=new BigInteger("0");
	b=bi(n);
	long[][] B=new long[A.length][A[0].length];
	for(int i=0;i<A.length;i++){
		B[i][i]=1;
	}
	while(b.compareTo(BigInteger.valueOf(1))>=0){
		if((b.remainder(BigInteger.valueOf(10)).compareTo(BigInteger.valueOf(1)))==0){
			B=MtPrd(A,B);
			b=b.subtract(BigInteger.valueOf(-1));
			b=b.divide(BigInteger.valueOf(10));
		}else if((b.remainder(BigInteger.valueOf(10)).compareTo(BigInteger.valueOf(1)))!=0){
			b=b.divide(BigInteger.valueOf(10));
		}
		A=MtPrd(A,A);
	}
	return B;
}
}