import sys
input = sys.stdin.readline

def Matprod(A, B, mod, N):
    temp = [0] * N*N
    for i in range(N):
        for j in range(N):
            ij = i * N + j
            for k in range(N):
                temp[ij] += A[i*N+k] * B[k*N+j]
                temp[ij] %= mod
    return temp

def Matpow_Linear(A, M, mod, N):
    Mat = [0] * N*N
    for i in range(N):
        Mat[i*N+i] = 1
         
    while M:
        if M & 1:
            Mat = Matprod(Mat, A, mod, N)
        A = Matprod(A, A, mod, N)
        M >>= 1
    return Mat  

N = int(input())
A = [1, 1, 1, 0]
mod = 998244353
A = Matpow_Linear(A, N, mod, 2)
print((A[0] - 1) % mod)