def fibonacci(n):
    a, b = 1, 0
    for _ in range(0, n):
        a, b = b, a + b
    return b

n=int(input())
n+=1
print(fibonacci(n)) def fibonacci(n):
    a, b = 1, 0
    for _ in range(0, n):
        a, b = b, a + b
    return b fibonacci a, b = 1, 0 a 1 b 0 for _ in range(0, n):
        a, b = b, a + b
     _ range(0, n) range 0 n a, b = b, a + b a b b a + b a b return b b n n n=int(input()) n int(input()) int input() input n+=1 n 1 print(fibonacci(n)) print fibonacci(n) fibonacci n def fibonacci(n):
    a, b = 1, 0
    for _ in range(0, n):
        a, b = b, a + b
    return b def fibonacci(n):
    a, b = 1, 0
    for _ in range(0, n):
        a, b = b, a + b
    return b fibonacci n+=1 1 n n=int(input()) int(input()) n
def fibonacci(n):
    a, b = 1, 0
    for _ in range(0, n):
        a, b = b, a + b
    return b

n=int(input())
n+=1
print(fibonacci(n))
