def fib(n):
    if n == 0 or n == 1:
        ans[n] = 1
        return 1
    # ?????¢???????¨?????????????????´???§????????°?????????????????????
    if ans[n] != -1:
        return ans[n]

    ans[n] = fib(n-1) + fib(n-2)
    return ans[n]


N = int(input())
ans = [-1 for i in range(N+1)]
a = fib(N)
print(a) def fib(n):
    if n == 0 or n == 1:
        ans[n] = 1
        return 1
    # ?????¢???????¨?????????????????´???§????????°?????????????????????
    if ans[n] != -1:
        return ans[n]

    ans[n] = fib(n-1) + fib(n-2)
    return ans[n] fib if n == 0 or n == 1:
        ans[n] = 1
        return 1
    # ?????¢???????¨?????????????????´???§????????°?????????????????????
     n == 0 or n == 1 n == 0 n 0 n == 1 n 1 ans[n] = 1 ans[n] ans n 1 return 1 1 if ans[n] != -1:
        return ans[n]

     ans[n] != -1 ans[n] ans n -1 return ans[n] ans[n] ans n ans[n] = fib(n-1) + fib(n-2) ans[n] ans n fib(n-1) + fib(n-2) fib(n-1) fib n-1 n 1 fib(n-2) fib n-2 n 2 return ans[n] ans[n] ans n n n N = int(input()) N int(input()) int input() input -1 for i in range(N+1) for i in range(N+1) i range(N+1) range N+1 N 1 for i in range(N+1) -1 ans = [-1 for i in range(N+1)] ans [-1 for i in range(N+1)] a = fib(N) a fib(N) fib N print(a) print a N = int(input()) int(input()) N a = fib(N) fib(N) a def fib(n):
    if n == 0 or n == 1:
        ans[n] = 1
        return 1
    # ?????¢???????¨?????????????????´???§????????°?????????????????????
    if ans[n] != -1:
        return ans[n]

    ans[n] = fib(n-1) + fib(n-2)
    return ans[n] def fib(n):
    if n == 0 or n == 1:
        ans[n] = 1
        return 1
    # ?????¢???????¨?????????????????´???§????????°?????????????????????
    if ans[n] != -1:
        return ans[n]

    ans[n] = fib(n-1) + fib(n-2)
    return ans[n] fib ans = [-1 for i in range(N+1)] [-1 for i in range(N+1)] ans
def fib(n):
    if n == 0 or n == 1:
        ans[n] = 1
        return 1
    # ?????¢???????¨?????????????????´???§????????°?????????????????????
    if ans[n] != -1:
        return ans[n]

    ans[n] = fib(n-1) + fib(n-2)
    return ans[n]


N = int(input())
ans = [-1 for i in range(N+1)]
a = fib(N)
print(a)