// No.135 とりあえず1次元の問題
// https://yukicoder.me/problems/no/135
//
#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;

int main() {
    unsigned int N;
    cin >> N;

    priority_queue<int> pq;
    for (auto i = 0; i < N; ++i) {
        int t;
        cin >> t;
        pq.push(t);
    }

    const int MIN_DIFF_INIT = 999999999;
    int min_diff = MIN_DIFF_INIT;
    int prev = pq.top();
    pq.pop();

    while (!pq.empty()) {
        int current = pq.top();
        pq.pop();
        if (current != prev) {
            min_diff = min(prev - current, min_diff);
            prev = current;
        }
    }

    if (min_diff != MIN_DIFF_INIT)
        cout << min_diff << endl;
    else
        cout << 0 << endl;
}