package main

func decode(encoded []int) []int {
	n := len(encoded) + 1
	xorSum := 0 
	for i := 1 ; i <= n ; i ++ {
		xorSum ^= i
	}
	oddXorSum := 0
	for i := 1; i < n ; i += 2 {
		oddXorSum ^= encoded[i]
	}
	firstNum := xorSum ^ oddXorSum
	res := []int{firstNum}
	for _, v := range encoded {
		last := res[len(res)-1]
		res = append(res, v ^ last)
	}
	return res
}

func main() {

}