n=int(input())
a=list(range(n+1))
a[0]=1
i=2
while i<=n:
    a[i]=a[i-1]+a[i-2]
    i+=1
print(a[n]) n=int(input()) n int(input()) int input() input a=list(range(n+1)) a list(range(n+1)) list range(n+1) range n+1 n 1 a[0]=1 a[0] a 0 1 i=2 i 2 while i<=n:
    a[i]=a[i-1]+a[i-2]
    i+=1 i<=n i n a[i]=a[i-1]+a[i-2] a[i] a i a[i-1]+a[i-2] a[i-1] a i-1 i 1 a[i-2] a i-2 i 2 i+=1 i 1 print(a[n]) print a[n] a n n=int(input()) int(input()) n i+=1 1 i a=list(range(n+1)) list(range(n+1)) a i=2 2 i
n=int(input())
a=list(range(n+1))
a[0]=1
i=2
while i<=n:
    a[i]=a[i-1]+a[i-2]
    i+=1
print(a[n])
