Remove Duplicates

Time limit5sMemory limit8 MB

Summary

Read a space-separated list whose length is not given, keep each value only at its first occurrence, and print the surviving values in order.

Level: Medium4 of 10
Topics: Hash map, Array, Implementation, Bit manipulation
Solved: No attempts yet

Problem

You are given $N$ integers $A_1, A_2, \ldots, A_N$ . Remove every number that has already appeared earlier, and print the remaining $N'$ numbers $B_1, B_2, \ldots, B_{N'}$ in input order. In other words, each value is printed once, at the position where it first appears.

$0 \le A_i < 2^{25} = 33554432$ for $i = 1, 2, \ldots, N$ .
The count $N$ is between 1 and 5,000,000 inclusive.

Input

The first line contains $A_1, A_2, \ldots, A_N$ separated by spaces. $N$ itself is not given.

Output

Print $B_1, B_2, \ldots, B_{N'}$ on one line, separated by spaces.

Hint

Watch the memory limit.

Examples2

Example 1

Input

12 1 449 12 555 1201 912 555 19372

Expected output

12 1 449 555 1201 912 19372

Example 2

Input

21003957 20891590 11382885 18340118 11354168 5461061 12693617 2552341 14639514 25224366 19239852 136782 17206566 18675414 9536557 24961835 2507460 32083310 4485200 19506627 21087117 9270314 12953612 10216350 8170712 20436397 11382885 29305594 27169105

Expected output

21003957 20891590 11382885 18340118 11354168 5461061 12693617 2552341 14639514 25224366 19239852 136782 17206566 18675414 9536557 24961835 2507460 32083310 4485200 19506627 21087117 9270314 12953612 10216350 8170712 20436397 29305594 27169105