https://www.acmicpc.net/problem/2748
import sys
n=int(sys.stdin.readline())
mlist=[]
num=0
for i in range(n+1):
if i==0:
num=0
elif i==1:
num=1
else:
num=mlist[-2]+mlist[-1]
mlist.append(num)
print(mlist[-1])
def myFun(n):
if n==0:
return 0
elif n==1:
return 1
elif n>1:
return myFun(n-2)+myFun(n-1)
n=int(input())
print(myFun(n))