def solve(n):
    dp=[1]*(n+1)
    for i in range(2,n+1):
        dp[i]=dp[i-1]+dp[i-2]
    return dp[n]
n=int(input())
print(solve(n)) def solve(n):
    dp=[1]*(n+1)
    for i in range(2,n+1):
        dp[i]=dp[i-1]+dp[i-2]
    return dp[n] solve dp=[1]*(n+1) dp [1]*(n+1) [1] 1 n+1 n 1 for i in range(2,n+1):
        dp[i]=dp[i-1]+dp[i-2]
     i range(2,n+1) range 2 n+1 n 1 dp[i]=dp[i-1]+dp[i-2] dp[i] dp i dp[i-1]+dp[i-2] dp[i-1] dp i-1 i 1 dp[i-2] dp i-2 i 2 return dp[n] dp[n] dp n n n n=int(input()) n int(input()) int input() input print(solve(n)) print solve(n) solve n def solve(n):
    dp=[1]*(n+1)
    for i in range(2,n+1):
        dp[i]=dp[i-1]+dp[i-2]
    return dp[n] def solve(n):
    dp=[1]*(n+1)
    for i in range(2,n+1):
        dp[i]=dp[i-1]+dp[i-2]
    return dp[n] solve n=int(input()) int(input()) n
def solve(n):
    dp=[1]*(n+1)
    for i in range(2,n+1):
        dp[i]=dp[i-1]+dp[i-2]
    return dp[n]
n=int(input())
print(solve(n))
