#include<bits/stdc++.h>
using lint=long long;
int main(){
    std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false);
    std::cout.setf(std::ios_base::fixed);std::cout.precision(15);
    lint n;std::cin>>n;
    if(n==1){
        std::cout<<1<<'\n';
        return 0;
    }
    lint mod=1'000'000'007;
    std::vector<lint>a(n+1,0);
    a.at(0)=1;
    a.at(2)=1;
    for(lint i=3;i<=n;i++){
        a.at(i)=(a.at(i-3)+a.at(i-2))%mod;
    }
    std::cout<<(a.at(n-2)+a.at(n-1)+a.at(n))%mod<<'\n';
}