# coding: utf-8



N = int(input())

L = [2, 1]



for i in range(90):

    L += [L[-2] + L[-1]]



print(L[N])

# coding: utf-8



def Lucas(n):

    a, b, c = 2, 1, 3

    while n != 0:

        a, b, c = b, c, b+c

        n -=1

    

    print(a)



Lucas(int(input()))

# coding: utf-8
N = int(input())
L = [2, 1]
for i in range(90):
    L += [L[-2] + L[-1]]
print(L[N])

# coding: utf-8
def Lucas(n):
    a, b, c = 2, 1, 3
    while n != 0:
        a, b, c = b, c, b + c
        n -= 1
    print(a)


Lucas(int(input()))

-N = int(input()) -L = [2, 1] -for i in range(90): -    L += [L[-2] + L[-1]] -print(L[N]) +def Lucas(n): +    a, b, c = 2, 1, 3 +    while n != 0: +        a, b, c = b, c, b + c +        n -= 1 +    print(a) + + +Lucas(int(input()))