package main

import . "fmt"
import . "sort"

func main() {
	var n int
	Scan(&n)
	a := make([]int, n)
	for i:=range a {
		Scan(&a[i])
	}
	Ints(a)
	ans := 0
	for i,v := range a {
		x := (i+1)-v
		if x<0{
			ans-=x
		} else {
			ans+=x
		}
	}
	Println(ans)
}