#include <iostream>
#include <vector>
#include <map>
#include <utility>
#define repeat_from(i,m,n) for (int i = (m); (i) < (n); ++(i))
typedef long long ll;
using namespace std;
const int mod = 1000;
int main() {
    int n; cin >> n;
    vector<int> g;
    map<pair<int,int>,int> adj;
    g.push_back(2);
    g.push_back(2);
    adj[make_pair(g[0], g[1])] = 2;
    repeat_from (i,2,n+1) {
        g.push_back((2 * g[i-1] + 2 * g[i-2]) % mod);
        pair<int,int> key = { g[i-1], g[i] };
        if (adj.count(key)) {
            int l = adj[key]; // g[p] == g[i+1]
            int r = i+1;
            int j = (n - l) % (r - l) + l;
            cout << (g[j] - (n%2 ? 0 : 1) + mod) % mod << endl;
            return 0;
        }
        adj[key] = i+1;
    }
    cout << (g[n] - (n%2 ? 0 : 1) + mod) % mod << endl;
    return 0;
}