#include <algorithm>
#include <cmath>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <vector>
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)
using namespace std;
typedef long long int lli;
lli MOD = 1000000007;
struct Matrix {
    vector<lli> a;
    lli n;
    lli mod = 1000;
    Matrix(lli n) : n(n)
    {
        a.assign(n * n, 0);
    };
    Matrix operator*(const Matrix r) const
    {
        Matrix v(n);
        rep(i, n) rep(j, n) rep(k, n)
        {
            v.a[i * n + j] += a[i * n + k] * r.a[k * n + j];
            v.a[i * n + j] %= mod;
        }
        return v;
    }
    Matrix operator+(const Matrix r) const
    {
        Matrix v(n);
        rep(i, n) rep(j, n)
        {
            v.a[i * n + j] = (a[i * n + j] + r.a[i * n + j]) % mod;
        }
        return v;
    }
    void set(int b, int d, int c)
    {
        a[b * n + d] = c;
    }
    void operator*=(const Matrix r)
    {
        Matrix v(n);
        rep(i, n) rep(j, n) rep(k, n)
        {
            v.a[i * n + j] += a[i * n + k] * r.a[k * n + j];
            v.a[i * n + j] %= mod;
        }
        *this = v;
    }
    void show()
    {
        rep(i, n) rep(j, n)
        {
            cout << a[i * n + j] << ' ';
            if (j == n - 1)
                cout << endl;
        }
    }
};
Matrix idn(lli n)
{
    Matrix a(n);
    rep(i, n)
    {
        a.a[i * n + i] = 1;
    }
    return a;
}
Matrix pow_mat(Matrix a, lli n)
{
    Matrix an = idn(a.n);
    while (n > 0) {
        if (n & 1)
            an *= a;
        a *= a;
        n /= 2;
    }
    return an;
}
int main()
{
    Matrix g(2);
    g.set(0, 0, 2);
    g.set(0, 1, 2);
    g.set(1, 0, 1);
    lli n;
    cin >> n;
    g = pow_mat(g, n - 1);
    if (n == 1) {
        cout << 2 << endl;
    } else if (n == 2) {
        cout << 7 << endl;
    } else if (n == 3) {
        cout << 20 << endl;
    } else if (n == 4) {
        cout << 55 << endl;
    } else {
        int a;
        if (n & 1)
            a = 0;
        else
            a = 1;
        cout << (g.a[0] * 2 + g.a[1] * 2 - a + 1000) % 1000 << endl;
    }
}