#include <iostream>
#include <cstdint>

typedef int_fast32_t int32;
int main() {
    int32 front[3]={0,1,0};
    int32 back[3]={1,0,0};
    int32 n;
    std::cin>>n;
    std::cout<<"n="<<n<<std::endl;
    if(n==1){
	std::cout<<1<<std::endl;
        return 0;
    }
    n-=2;
    for(int32 i=0;i<n;i++){
	back[0]=front[0] % 1000000007;
	back[1]=front[1] % 1000000007;
	back[2]=front[2] % 1000000007;
	front[0]=back[2];
	front[1]=back[0]+back[2];
	front[2]=back[1];
    }    int32 front_sum;
    for(int i=0;i<3;i++){
	front_sum+=front[i] % 1000000007;
    }
    front_sum%=1000000007;
    int32 back_sum=(back[0]+back[1]+back[2]) % 1000000007;    std::cout<<(back_sum+front_sum) % 1000000007<<std::endl;
    return 0;
}