#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    int temp;
    cin>>n;
    set<int> x;
    for(int i=0;i<n;i++){
        cin>>temp;
        x.insert(temp);
    }
    vector<int> t;
    adjacent_difference(x.begin(), x.end(), back_inserter(t));
    cout<<*min_element(t.begin()+1,t.end())<<endl;
    return 0;
}