import java.util.*;

public class Run {
    public static void main (String arg[]) {
        Scanner scan = new Scanner(System.in);
        int N = scan.nextInt();
        ArrayList<Integer> X = new ArrayList<>();
        for (int i = 0; i < N; i++) {
            X.add(scan.nextInt());
        }
        Collections.sort(X);
        int min = X.get(1) - X.get(0);
        int tmp;
        for (int i = 1; i < N - 1; i++) {
            tmp = X.get(i+1) - X.get(i);
            if (tmp!=0 && (min==0 || tmp < min)) min = tmp;
        }
        System.out.println(min);
    }
}