#!/usr/bin/python

n = int(input())

def fib(n):
    l = list()
    l.append(1)
    l.append(1)

    for i in range(2, n+1):
        l.append(l[i-1] + l[i-2])

    return l[-1]

print(fib(n)) n = int(input()) n int(input()) int input() input def fib(n):
    l = list()
    l.append(1)
    l.append(1)

    for i in range(2, n+1):
        l.append(l[i-1] + l[i-2])

    return l[-1] fib l = list() l list() list l.append(1) l.append l append 1 l.append(1) l.append l append 1 for i in range(2, n+1):
        l.append(l[i-1] + l[i-2])

     i range(2, n+1) range 2 n+1 n 1 l.append(l[i-1] + l[i-2]) l.append l append l[i-1] + l[i-2] l[i-1] l i-1 i 1 l[i-2] l i-2 i 2 return l[-1] l[-1] l -1 n n print(fib(n)) print fib(n) fib n n = int(input()) int(input()) n def fib(n):
    l = list()
    l.append(1)
    l.append(1)

    for i in range(2, n+1):
        l.append(l[i-1] + l[i-2])

    return l[-1] def fib(n):
    l = list()
    l.append(1)
    l.append(1)

    for i in range(2, n+1):
        l.append(l[i-1] + l[i-2])

    return l[-1] fib
#!/usr/bin/python

n = int(input())

def fib(n):
    l = list()
    l.append(1)
    l.append(1)

    for i in range(2, n+1):
        l.append(l[i-1] + l[i-2])

    return l[-1]

print(fib(n))