n = int(input())

dp = [0]*(45)
dp[0] = 1
dp[1] = 1
def fib(i):
    j = 2
    while j <= i:
        if j >= 2:
            dp[j] = dp[j-1] + dp[j-2]
        j += 1

fib(n)
print(dp[n])
 n = int(input()) n int(input()) int input() input dp = [0]*(45) dp [0]*(45) [0] 0 45 dp[0] = 1 dp[0] dp 0 1 dp[1] = 1 dp[1] dp 1 1 def fib(i):
    j = 2
    while j <= i:
        if j >= 2:
            dp[j] = dp[j-1] + dp[j-2]
        j += 1 fib j = 2 j 2 while j <= i:
        if j >= 2:
            dp[j] = dp[j-1] + dp[j-2]
        j += 1 j <= i j i if j >= 2:
            dp[j] = dp[j-1] + dp[j-2]
         j >= 2 j 2 dp[j] = dp[j-1] + dp[j-2] dp[j] dp j dp[j-1] + dp[j-2] dp[j-1] dp j-1 j 1 dp[j-2] dp j-2 j 2 j += 1 j 1 i i fib(n) fib n print(dp[n]) print dp[n] dp n n = int(input()) int(input()) n dp = [0]*(45) [0]*(45) dp def fib(i):
    j = 2
    while j <= i:
        if j >= 2:
            dp[j] = dp[j-1] + dp[j-2]
        j += 1 def fib(i):
    j = 2
    while j <= i:
        if j >= 2:
            dp[j] = dp[j-1] + dp[j-2]
        j += 1 fib
n = int(input())

dp = [0]*(45)
dp[0] = 1
dp[1] = 1
def fib(i):
    j = 2
    while j <= i:
        if j >= 2:
            dp[j] = dp[j-1] + dp[j-2]
        j += 1

fib(n)
print(dp[n])

