#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(a);i>=(b);i--)
#define pb push_back

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef set<int> si;
const int mod = 1e3;
ll n, m;
int a[2] = {1,0}, b[2] = {1,1}, c[2];

void merge(int (&a)[2], int (&b)[2]){
  c[0] = (a[0] * b[0] + a[1] * b[1] * 3) % mod;
  c[1] = (a[0] * b[1] + a[1] * b[0]) % mod;
  a[0] = c[0];
  a[1] = c[1];
}
main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> n;
  m = n;
  while (n > 0){
    if (n & 1 > 0){
      merge(a, b);
    }
    merge(b, b);
    n >>= 1;
  }
  a[0] *= 2;
  if(m%2 == 0)a[0] += mod - 1;
  cout << a[0] % mod << endl;
}