import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int [] X = new int [N];
        for(int i=0; i<N; i++){
            X[i] = sc.nextInt();
        }
        Arrays.sort(X);
        int min = X[N-1];
        for(int i=1; i<N; i++){
            int temp = X[i]-X[i-1];
            if(temp!=0 && min>temp){
                min = temp;
            }
        }
        if( min!=X[N-1] ){
            System.out.println(min);
        }else{
            System.out.println(0);
        }
    }
}