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