#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MOD = 1000000007;

#define REP(i,n) for((i)=0;(i)<(int)(n);(i)++)

ll dp[1000010];

int main(){
    int n;
    cin >> n;
    
    dp[1] = 1;
    dp[2] = dp[3] = 2;
    for (int i = 4; i <= n; i++) dp[i] = (dp[i - 2] + dp[i - 3]) % MOD;

    cout << dp[n] << endl;

    return 0;
}