package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan(); n, _ := strconv.Atoi(sc.Text())

	mod := 1000000007
	if n >= 2 {
		k1 := 1
		k2 := 0
		p := 0
		for i := 0; i < n - 1; i++ {
			k1, k2, p = p, k1, k1 + k2 % mod
		}
		fmt.Println((k1 + k2 + p) % mod)
	} else {
		fmt.Println(1)
	}
}