#include<bits/stdc++.h>
int dp[3][1000000];
main(){
    dp[0][0] = 1;
    dp[1][1] = 1;
    dp[2][2] = 1;
    dp[0][2] = 1;
    dp[1][2] = 1;
    for(int i = 3;i < 1000000;i++){
        dp[0][i] = (dp[1][i-1] + dp[2][i-1])%1000000007;
        dp[1][i] = (dp[0][i-2] + dp[2][i-2])%1000000007;
        dp[2][i] = (dp[0][i-3] + dp[1][i-3])%1000000007;
    }
    int N,sum=0;
    scanf("%d",&N);
    for(int i = 0;i < 3;i++){
        sum = (sum+dp[i][N-1])%1000000007;
    }
    printf("%d\n",sum);
}