# 1 1 2 3 5 8 13
def feibo(n):
if n==1 or n==2:
return 1
if list[n]!=0:
return list[n]
else:
a=(feibo(n-1)+feibo(n-2))%(1000000007)
list[n]=a
return a
n=int(input())
list=[0]*(n+1)
b=feibo(n)
print(b)