import java.util.Scanner;

class BiMtx {
	int a,b,c,d;

	void set(int p, int q, int r, int s){
		a=p;
		b=q;
		c=r;
		d=s;
	}
	void set(BiMtx A){
		a = A.a;
		b = A.b;
		c = A.c;
		d = A.d;
	}

	BiMtx (int p, int q, int r, int s){
		set(p,q,r,s);
	}
}

class BiMtxPow {
	BiMtx BMmulti (BiMtx A, BiMtx B){
		BiMtx C = new BiMtx(0,0,0,0);
		C.a = (A.a * B.a + A.b * B.c) % 1000;
		C.b = (A.a * B.b + A.b * B.d) % 1000;
		C.c = (A.c * B.a + A.d * B.c) % 1000;
		C.d = (A.c * B.b + A.d * B.d) % 1000;
		return C;
	}

	BiMtx BMpow (BiMtx A, long n){
		BiMtx C = new BiMtx(0,0,0,0);
		BiMtx half = new BiMtx(0,0,0,0);
		if(n == 0){
			C.set(1, 0, 0, 1);
			return C;
		}else if (n == 1){
			C.set(A);
			return C;
		}else if((n>>1)<<1 == n){
			half = BMpow(A,(n>>1));
			return BMmulti(half,half);
		}else{
			half = BMpow(A,(n>>1));
			return BMmulti(half,BMmulti(half,A));
		}
	}
}

class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long n = sc.nextLong();
		sc.close();

		BiMtx A = new BiMtx(0,1,2,2);
		BiMtx C = new BiMtx(0,0,0,0);
		BiMtxPow bmp = new BiMtxPow();

		C = bmp.BMmulti(A, A);
		C = bmp.BMpow(A, n);

		if(n%2==0)System.out.println((2*C.a + 2* C.b -1) % 1000);
		else System.out.println((2*C.a + 2* C.b) % 1000);
	}

}