#include<bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

const int M = 1000;

struct Number {
    int c, r3;
};

Number operator*(Number a, Number b) {
    return {
        (a.c * b.c + 3 * a.r3 * b.r3) % M,
        (a.c * b.r3 + a.r3 * b.c) % M
    };
}
Number operator^(Number a, ULL i) {
    if (i == 0) return { 1,0 };
    Number res = (a * a) ^ (i / 2);
    if (i % 2 == 1) res = res * a;
    return res;
}

int main() {
    ULL N; cin >> N;
    Number X = { 1,1 };
    X = X ^ N;
    if(N % 2 == 0) cout << ((X.c * 2 - 1) % M) << endl;
    else cout << (X.c * 2 % M) << endl;
    return 0;
}