import string
import sys
from typing import Generator, List, Tuple


def input(): return sys.stdin.readline().rstrip('\n')


def main():
    M = 10 ** 9 + 7
    n = int(input())
    d = [(0, 0, 0)] * (n + 1)
    for i in range(1, n + 1):
        a = 1 if i == 1 else 0
        b = 1 if i == 2 else 0
        c = 1 if i == 3 else 0
        if i >= 1:
            a += d[i - 1][1] + d[i - 1][2]
        if i >= 2:
            b += d[i - 2][0] + d[i - 2][2]
        if i >= 3:
            c += d[i - 3][0] + d[i - 3][1]
        d[i] = (a % M, b % M, c % M)

    return sum(d[-1]) % M


if __name__ == '__main__':
    ret = main()


    def out(x):
        if isinstance(x, List) or isinstance(x, Tuple):
            print(*x)
        else:
            print(x)


    if ret is None:
        pass
    elif isinstance(ret, Generator):
        for val in ret:
            out(val)
    else:
        out(ret)