import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import static java.lang.System.in;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        int N = Integer.parseInt(reader.readLine());
        String[] inputs = reader.readLine().split(" ");
        long minDistance = Long.MAX_VALUE;
        boolean found = false;
        for (int i = 0; i < N; i++) {
            for (int j = i + 1; j < N; j++) {
                long x = Long.parseLong(inputs[i]);
                long y = Long.parseLong(inputs[j]);
                if(x != y) {
                    minDistance = Math.min(minDistance, Math.abs(x - y));
                    found = true;
                }

            }
        }
        if (found) {
            System.out.println(minDistance);
        } else {
            System.out.println(0);
        }

    }
}