#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)n; i++)
#define repp(i, m, n) for (int i = (int)m; i < (int)n; i++)
#define all(v) begin(v), end(v)
using namespace std;
using ll = long long int;

int N, X[1000001] = {0};

int main() {
    // 入力
    cin >> N;
    rep(i, N) { int x; cin >> x; X[x]++; }

    // 点
    vector<int> v;
    rep(i, 1000001) if (X[i] != 0) v.push_back(i);

    // 出力
    if (v.size() == 1) cout << 0 << endl;
    else {
        int Min = 10000000;
        for (int i = 0; i < v.size() - 1; i++) Min = min(Min, v[i + 1] - v[i]);
        cout << Min << endl;
    }
}