# coding: utf-8
# Here your code !

N=int(input())
print(N)
F=[]
A=[]

for i in range(3):
    F.append(1)
    A.append(1)
    
for i in range(3,N+1):
    F.append(F[i-1]+F[i-2])
    if i%2==0:
        A.append(F[i]-F[i//2]*F[i//2])
    else:
        A.append(F[i])


print(A[N])