#include <bits/stdc++.h>
using namespace std;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(i,a,b) for (int i = (a); i < (b); i++)
#define RFOR(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define REP(i,n) for (int i = 0; i < (n); i++)
#define RREP(i,n) for (int i = (n)-1; i >= 0; i--)
#define ALL(x) (x).begin(), (x).end()
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define RITR(x,c) for(__typeof(c.rbegin()) x=c.rbegin();x!=c.rend();x++)
#define BIT(n) (1LL<<(n))
#define SZ(x) ((int)(x).size())
typedef long long ll;
// -------------------------------------

int N;

int A[2][2];

const long long mod = 1000;

// kmjp さんのブログと蟻本を見てやっと解けました...
const int MAT=2;
struct Mat { ll v[MAT][MAT]; };
Mat mulmat(Mat& a,Mat& b,int n=MAT) {
    Mat r;
    REP(x,n) REP(y,n) r.v[x][y]=0;
    REP(x,n) REP(z,n) REP(y,n) r.v[x][y] += (a.v[x][z]*b.v[z][y]) % mod;
    REP(x,n) REP(y,n) r.v[x][y]%=mod;
    return r;
}

Mat powmat(ll p,Mat a,int n=MAT) {
    Mat r;
    REP(x,n) REP(y,n) r.v[x][y]=0;
    REP(i,n) r.v[i][i]=1;
    while(p) {
        if(p%2) r=mulmat(r,a,n);
        a=mulmat(a,a,n);
        p>>=1;
    }
    return r;
}

int main() {
  cin >> N;

  Mat a;
  a.v[0][0] = 1; a.v[0][1] = 3;
  a.v[1][0] = 1; a.v[1][1] = 1;

  Mat mn = powmat(N, a);

  ll an = mn.v[0][0];

  int ans = (an * 2 + mod - 1 + N%2) % mod;
  cout << ans << endl;

  return 0;
}