#include <bits/stdc++.h> 

using namespace std;

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    int n, t;
    vector <int> v;

    cin >> n;

    for (int i = 0; i < n; i++)
    {
        cin >> t;
        v.push_back(t);
    }

    sort(v.begin(), v.end());

    int res = 1e9;

    for (int i = 1; i < n - 1; i++)
    {
        if (v[i - 1] != v[i])
        {
            res = min(res, abs(v[i] - v[i - 1]));
        }
        if (v[i + 1] != v[i])
        {
            res = min(res, abs(v[i] - v[i + 1]));
        }
    }
    
    if(res>=1e9) res = 0;

    cout << res << '\n';

    return 0;
}