# Xor-MST

Time Limit: 2 seconds

Memory Limit: 256 megabytes

## Description

You are given a complete undirected graph with n vertices. A number ai is assigned to each vertex, and the weight of an edge between vertices i and j is equal to aixoraj.

Calculate the weight of the minimum spanning tree in this graph.

## Input

The first line contains n (1 ≤ n ≤ 200000) — the number of vertices in the graph.

The second line contains n integers a1, a2, ..., an (0 ≤ ai < 230) — the numbers assigned to the vertices.

## Output

Print one number — the weight of the minimum spanning tree in the graph.

## Sample Input

Input51 2 3 4 5Output8Input41 2 3 4Output8

## Sample Output

None

None

None