#coding:utf-8
#1_10_A
def fibo(n, numbers):
    if n == 0 or n == 1:
        numbers[n] = 1
        return numbers[n]
    elif numbers[n]:
        return numbers[n]
    else:
        numbers[n] = fibo(n - 1, numbers) + fibo(n - 2, numbers)
        return numbers[n]

n = int(input())
fibonacci_numbers = [0 for i in range(n + 1)]
print(fibo(n, fibonacci_numbers)) def fibo(n, numbers):
    if n == 0 or n == 1:
        numbers[n] = 1
        return numbers[n]
    elif numbers[n]:
        return numbers[n]
    else:
        numbers[n] = fibo(n - 1, numbers) + fibo(n - 2, numbers)
        return numbers[n] fibo if n == 0 or n == 1:
        numbers[n] = 1
        return numbers[n]
    elif numbers[n]:
        return numbers[n]
    else:
        numbers[n] = fibo(n - 1, numbers) + fibo(n - 2, numbers)
        return numbers[n] n == 0 or n == 1 n == 0 n 0 n == 1 n 1 numbers[n] = 1 numbers[n] numbers n 1 return numbers[n] numbers[n] numbers n elif numbers[n]:
        return numbers[n]
     numbers[n] numbers n return numbers[n] numbers[n] numbers n numbers[n] = fibo(n - 1, numbers) + fibo(n - 2, numbers) numbers[n] numbers n fibo(n - 1, numbers) + fibo(n - 2, numbers) fibo(n - 1, numbers) fibo n - 1 n 1 numbers fibo(n - 2, numbers) fibo n - 2 n 2 numbers return numbers[n] numbers[n] numbers n n n numbers numbers n = int(input()) n int(input()) int input() input 0 for i in range(n + 1) for i in range(n + 1) i range(n + 1) range n + 1 n 1 for i in range(n + 1) 0 fibonacci_numbers = [0 for i in range(n + 1)] fibonacci_numbers [0 for i in range(n + 1)] print(fibo(n, fibonacci_numbers)) print fibo(n, fibonacci_numbers) fibo n fibonacci_numbers n = int(input()) int(input()) n fibonacci_numbers = [0 for i in range(n + 1)] [0 for i in range(n + 1)] fibonacci_numbers def fibo(n, numbers):
    if n == 0 or n == 1:
        numbers[n] = 1
        return numbers[n]
    elif numbers[n]:
        return numbers[n]
    else:
        numbers[n] = fibo(n - 1, numbers) + fibo(n - 2, numbers)
        return numbers[n] def fibo(n, numbers):
    if n == 0 or n == 1:
        numbers[n] = 1
        return numbers[n]
    elif numbers[n]:
        return numbers[n]
    else:
        numbers[n] = fibo(n - 1, numbers) + fibo(n - 2, numbers)
        return numbers[n] fibo
#coding:utf-8
#1_10_A
def fibo(n, numbers):
    if n == 0 or n == 1:
        numbers[n] = 1
        return numbers[n]
    elif numbers[n]:
        return numbers[n]
    else:
        numbers[n] = fibo(n - 1, numbers) + fibo(n - 2, numbers)
        return numbers[n]

n = int(input())
fibonacci_numbers = [0 for i in range(n + 1)]
print(fibo(n, fibonacci_numbers))