package main

import . "fmt"
import . "math"

func main() {
	var k float64
	Scan(&k)
	var ans float64
	for n := 1; n < 1e7; n++ {
		fn := float64(n)
		ans += Sin(k*fn)/Pow(fn,fn)
	}
	Printf("%.20f\n", ans)
}