import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]

def main():
    def com(com_n, com_r):
        return fac[com_n] * inv[com_r] * inv[com_n - com_r] % md

    def pat(n):
        if n < 3: return 2
        if memo[n] != -1: return memo[n]
        res = 0
        for m in range(n):
            res += pat(m) * pat(n - 1 - m) * com(n - 1, m) * inv4
            res %= md
        memo[n] = res
        return res

    md = 10 ** 9 + 7
    inv4 = pow(4, md - 2, md)
    n = II()
    if n < 3:
        print(0)
        exit()

    # combinationの準備
    n_max = n + 1
    fac = [1]
    inv = [1] * (n_max + 1)
    k_fac_inv = 1
    for i in range(1, n_max + 1):
        k_fac_inv = k_fac_inv * i % md
        fac.append(k_fac_inv)
    k_fac_inv = pow(k_fac_inv, md - 2, md)
    for i in range(n_max, 1, -1):
        inv[i] = k_fac_inv
        k_fac_inv = k_fac_inv * i % md

    memo = [-1] * (n + 1)
    print(pat(n))

main()