
n=int(input())
f=[0]*45
def Fib(n):
    if n==0:
        return 1
    elif n==1:
        return 1
    else:
        if f[n]!=0:
            return f[n]
        else:
            f[n]=Fib(n-1)+Fib(n-2)
            return f[n]
print(Fib(n))
     n=int(input()) n int(input()) int input() input f=[0]*45 f [0]*45 [0] 0 45 def Fib(n):
    if n==0:
        return 1
    elif n==1:
        return 1
    else:
        if f[n]!=0:
            return f[n]
        else:
            f[n]=Fib(n-1)+Fib(n-2)
            return f[n] Fib if n==0:
        return 1
    elif n==1:
        return 1
    else:
        if f[n]!=0:
            return f[n]
        else:
            f[n]=Fib(n-1)+Fib(n-2)
            return f[n] n==0 n 0 return 1 1 elif n==1:
        return 1
     n==1 n 1 return 1 1 if f[n]!=0:
            return f[n]
        else:
            f[n]=Fib(n-1)+Fib(n-2)
            return f[n] f[n]!=0 f[n] f n 0 return f[n] f[n] f n f[n]=Fib(n-1)+Fib(n-2) f[n] f n Fib(n-1)+Fib(n-2) Fib(n-1) Fib n-1 n 1 Fib(n-2) Fib n-2 n 2 return f[n] f[n] f n n n print(Fib(n)) print Fib(n) Fib n def Fib(n):
    if n==0:
        return 1
    elif n==1:
        return 1
    else:
        if f[n]!=0:
            return f[n]
        else:
            f[n]=Fib(n-1)+Fib(n-2)
            return f[n] def Fib(n):
    if n==0:
        return 1
    elif n==1:
        return 1
    else:
        if f[n]!=0:
            return f[n]
        else:
            f[n]=Fib(n-1)+Fib(n-2)
            return f[n] Fib n=int(input()) int(input()) n f=[0]*45 [0]*45 f

n=int(input())
f=[0]*45
def Fib(n):
    if n==0:
        return 1
    elif n==1:
        return 1
    else:
        if f[n]!=0:
            return f[n]
        else:
            f[n]=Fib(n-1)+Fib(n-2)
            return f[n]
print(Fib(n))
    
