import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 9; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

def mul(A, B):
	C = [[0] * len(B[0]) for i in range(len(A))]
	for i in range(len(A)):
		for k in range(len(B)):
			for j in range(len(B[0])):
				C[i][j] = (C[i][j] + A[i][k] * B[k][j])
	return C

def matrixPow(A, n, N):
	B = [[0] * N for i in range(N)]
	for i in range(N):
		B[i][i] = 1

	while n > 0:
		if n & 1 == 1:
			B = mul(A, B)
		A = mul(A, A)
		n = n >> 1

	return B


#処理内容
def main():
	N = int(input())
	A = [[19 / 4, -3], [1, 0]]

	B = matrixPow(A, N, 2)
	# print(B)
	anspre = mul(B, [[3], [4]])
	ans = anspre[1][0]
	print(ans)



if __name__ == '__main__':
	main()