#include<bits/stdc++.h>

using namespace std;

typedef long long ll;

int main(){
        const ll MOD = 1e9 + 7;
        int N;
        cin>>N;
        vector <ll> dp;
        dp.push_back(1);
        dp.push_back(2);
        dp.push_back(2);
        for(int i=3;i<N;i++){
                dp.push_back((dp[i-2]+dp[i-3])%MOD);
        }
        cout<<dp[N-1]<<endl;
}