import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

int readint() {
    return readln.chomp.to!int;
}

int[] readints() {
    return readln.split.map!(to!int).array;
}

void main() {
    const MOD = 1_000_000_007;

    int n = readint();

    auto dp = new long[][](n + 10, 3 + 1);
    dp[1][1] = dp[2][2] = dp[3][3] = 1;

    for (int i = 1; i < n; i++) {
        for (int j = 1; j <= 3; j++) {
            for (int k = 1; k <= 3; k++) {
                if (j == k)
                    continue;

                dp[i + k][k] = (dp[i + k][k] + dp[i][j]) % MOD;
            }
        }
    }

    long ans = (dp[n][1] + dp[n][2] + dp[n][3]) % MOD;
    writeln(ans);
}