Problem:
Unique

For a sequence of integers $A = \{a_0, a_1, ..., a_{n-1}\}$ which is sorted by ascending order, eliminate all equivalent elements.

Input

A sequence is given in the following format.

$n$
$a_0 \; a_1 \; ,..., \; a_{n-1}$

Output

Print the sequence after eliminating equivalent elements in a line. Separate adjacency elements by a space character.

Constraints

$1 \leq n \leq 100,000$

$-1000,000,000 \leq a_i \leq 1,000,000,000$

$a_0 \leq a_1 \leq ... \leq a_{n-1}$

Sample Input 1

4
1 2 2 4

Sample Output 1

1 2 4

Solution in Go (judge verdict: Accepted)

package main

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

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	n := getNextInt(scanner)
	aa := make([]int, n)
	for i := 0; i < n; i++ {
		aa[i] = getNextInt(scanner)
	}
	bb := make([]int, 0)
	l := 0
	for r := 0; r < n; r++ {
		for r > l && aa[l] != aa[r] {
			l++
		}
		if l == r {
			bb = append(bb, aa[l])
		}
	}
	for i := 0; i < len(bb); i++ {
		if i > 0 {
			fmt.Fprint(writer, " ")
		}
		fmt.Fprint(writer, bb[i])
	}
	fmt.Fprintln(writer, "")
}