write a go solution for Description:
Ran Yakumo is a cute girl who loves creating cute Maths problems.

Let f(x) be the minimal square number strictly greater than x, and g(x) be the maximal square number less than or equal to x. For example, f(1)=f(2)=g(4)=g(8)=4.

A positive integer x is cute if x-g(x)<f(x)-x. For example, 1,5,11 are cute integers, while 3,8,15 are not.

Ran gives you an array a of length n. She wants you to find the smallest non-negative integer k such that a_i+k is a cute number for any element of a.

Input Format:
The first line contains one integer n (1<=n<=10^6) — the length of a.

The second line contains n intergers a_1,a_2,ldots,a_n (1<=a_1<=a_2<=ldots<=a_n<=2*10^6) — the array a.

Output Format:
Print a single interger k — the answer.

Note:
Test case 1:

3 is not cute integer, so kne0.

2,4,9,11 are cute integers, so k=1.. Output only the code with no comments, explanation, or additional text.