package main

import . "fmt"
import . "math"

func sqrt(a int) int {
	x := int(Sqrt(float64(a)))
	if x*x < a {
		x++
	}
	if a < x*x {
		x--
	}
	return x
}

func main() {
	var n int
	Scan(&n)
	ans := sqrt(n)+2+(n-sqrt(n)*sqrt(n))
	Println(ans)
}