#include <bits/stdc++.h>
using namespace std;
int bin(int a, int b, int c) {
  a--;
  b++;
  while (b - a > 1) {
    long long m = (a + b) / 2;
    if (m * m > c)
      b = m;
    else
      a = m;
  }
  return a;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, ans = -1e9;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int a;
    cin >> a;
    if (bin(1, 1e9, a) * bin(1, 1e9, a) != a || a < 0) ans = max(ans, a);
  }
  cout << ans;
  return 0;
}

### Prompt

Construct a CPP code solution to the problem outlined:

Given an array a1, a2, ..., an of n integers, find the largest number in the array that is not a perfect square.

A number x is said to be a perfect square if there exists an integer y such that x = y2.

Input

The first line contains a single integer n (1 ≤ n ≤ 1000) — the number of elements in the array.

The second line contains n integers a1, a2, ..., an ( - 106 ≤ ai ≤ 106) — the elements of the array.

It is guaranteed that at least one element of the array is not a perfect square.

Output

Print the largest number in the array which is not a perfect square. It is guaranteed that an answer always exists.

Examples

Input

2
4 2


Output

2


Input

8
1 2 4 8 16 32 64 576


Output

32

Note

In the first sample case, 4 is a perfect square, so the largest number in the array that is not a perfect square is 2.

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int bin(int a, int b, int c) {
  a--;
  b++;
  while (b - a > 1) {
    long long m = (a + b) / 2;
    if (m * m > c)
      b = m;
    else
      a = m;
  }
  return a;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, ans = -1e9;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int a;
    cin >> a;
    if (bin(1, 1e9, a) * bin(1, 1e9, a) != a || a < 0) ans = max(ans, a);
  }
  cout << ans;
  return 0;
}

```