#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int a[1003];
  scanf("%d", &n);
  int maxx = -0x1f1f1f1f;
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    maxx = maxx < a[i] ? a[i] : maxx;
  }
  maxx = maxx ^ a[n - 1];
  printf("%d\n", maxx);
}

### Prompt

Develop a solution in Cpp to the problem described below:

DO YOU EXPECT ME TO FIND THIS OUT?

WHAT BASE AND/XOR LANGUAGE INCLUDES string?

DON'T BYTE OF MORE THAN YOU CAN CHEW

YOU CAN ONLY DISTORT THE LARGEST OF MATHEMATICS SO FAR

SAYING "ABRACADABRA" WITHOUT A MAGIC AND WON'T DO YOU ANY GOOD

THE LAST STACK RUPTURES. ALL DIE. OH, THE EMBARRASSMENT!

I HAVE NO ARRAY AND I MUST SCREAM

ELEMENTS MAY NOT BE STORED IN WEST HYPERSPACE

Input

The first line of input data contains a single integer n (1 ≤ n ≤ 10).

The second line of input data contains n space-separated integers ai (1 ≤ ai ≤ 11).

Output

Output a single integer.

Example

Input

4
2 5 3 1


Output

4

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int a[1003];
  scanf("%d", &n);
  int maxx = -0x1f1f1f1f;
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    maxx = maxx < a[i] ? a[i] : maxx;
  }
  maxx = maxx ^ a[n - 1];
  printf("%d\n", maxx);
}

```