递推（Python）

思路：经典递推板子题，中间再加个取mod操作即可

代码：

import sys
input = lambda: sys.stdin.readline().strip()

import math
inf = 10 ** 18

def I():
    return input()

def II():
    return int(input())

def MII():
    return map(int, input().split())

def LI():
    return input().split()

def LII():
    return list(map(int, input().split()))

def LFI():
    return list(map(float, input().split()))

fmax = lambda x, y: x if x > y else y
fmin = lambda x, y: x if x < y else y
isqrt = lambda x: int(math.sqrt(x))

'''

'''

def solve():
    mod = 10 ** 9 + 7
    k = II()
    f1 = f2 = 1
    for _ in range(3, k + 1):
        f1, f2 = f2 % mod, (f1 + f2) % mod
    print(f2)

t = 1
# t = II()
for _ in range(t):
    solve()