#include <cmath>
#include <iostream>
#include <vector>

class Matrix {
public:
	Matrix() :vector(4) {};
	Matrix(const std::vector<int> &vec) :vector(vec) {};
	Matrix dot_with_mod(const Matrix &right) const {
		Matrix res;
		res.vector.at(0) = (vector.at(0) * right.vector.at(0) + vector.at(1) * right.vector.at(2)) % 1000;
		res.vector.at(1) = (vector.at(0) * right.vector.at(1) + vector.at(1) * right.vector.at(3)) % 1000;
		res.vector.at(2) = (vector.at(2) * right.vector.at(0) + vector.at(3) * right.vector.at(2)) % 1000;
		res.vector.at(3) = (vector.at(2) * right.vector.at(1) + vector.at(3) * right.vector.at(3)) % 1000;
		return res;
	}
	int at(const int &n) const {
		return vector.at(n);
	}
private:
	std::vector<int> vector;
};
int a(const int &n) {
	int i = 0;
	while ((1 << ++i) < n) {	}
	Matrix res({ 1, 0, 0, 1 });
	Matrix mul({ 0, 1, 2, 2 });
	while (i >= 0) {
		res = res.dot_with_mod(res);
		if (((1 << i--) & n) != 0) {
			res = res.dot_with_mod(mul);
		}
	}
	auto result = (res.at(0) + res.at(1)) * 2;
	if ((n & 1) == 0) {
		return (result + 999) % 1000;
	}
	else {
		return result % 1000;
	}
}
int main() {
	int n;
	std::cin >> n;
	std::cout << a(n) << std::endl;
	return 0;
}