#include <stdio.h>

#define Z (1000000000+7)

int main()
{
        long int N;
        scanf( "%ld\n", &N );

        long int S, O, T;
        long int nS, nO, nT;
        S = 0;
        O = 1;
        T = 0;
        for( long int i = 2; i <= N; i++ ) {
                nS = O + T;
                nO = S;
                nT = O;
                S = nS % Z;
                O = nO % Z;
                T = nT % Z;
        }

        printf("%ld\n", (S+O+T)%Z );

        return 0;
}