#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <limits.h>
#define swap(type,a,b) do{type t=a;a=b;b=t;}while(0);
#define MAX(a,b) (((a)>(b))?(a):(b))
#define MIN(a,b) (((a)<(b))?(a):(b))
#define ll long long
#define INF 100000000
#define FOR(i,a,n) for(i=(a);i<(n);i++)
const int MOD=(1e+9)+7;
int comp(const void* a,const void* b){
	return *(int*)a-*(int*)b;
}
void fill(int a[],int b,int c){
	int i;
	FOR(i,0,b) a[i]=c;
	return;
}
ll dp[3][1000001];
int main(void)
{
	int n,i,j;
	scanf("%d",&n);
	dp[0][1]=dp[1][2]=dp[2][3]=1;
	FOR(i,3,n+1){
		FOR(j,0,3){
			dp[j][i]+=(dp[(j+1)%3][i-j-1]+dp[(j+2)%3][i-j-1])%MOD;
		}
	}
	printf("%lld\n",(dp[0][n]+dp[1][n]+dp[2][n])%MOD);
	return 0;
}