#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin >> n;

    set<int> st;
    for (int i = 0; i < n; ++i) {
        int t;
        cin >> t;
        st.insert(t);
    }

    vector<int> vt;
    adjacent_difference(st.begin(), st.end(), back_inserter(vt));
    cout << *min_element(vt.begin() + 1, vt.end()) << endl;
    return 0;
}