function Main(input) {
  const N = parseInt(input.trim())
  let dp = []
  dp[1] = 1
  dp[2] = 2
  dp[3] = 2
  for (let i = 4; i <= N; i++) {
    dp[i] = (dp[i - 2] + dp[i - 3]) % (10 ** 9 + 7)
  }
  console.log(dp[N])
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"))