import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

# 最後の パ ごとに

N = int(read())

MOD = 10 ** 9 + 7

dp = [0] * (N+10)

dp[:3] = 1,1,2

for n in range(3,N+10):
    dp[n] = (dp[n-2] + dp[n-3]) % MOD

print(dp[N])