import java.util.Scanner;
import java.util.Arrays;

class No_135 {
	public static void main(String args[]) {

		Scanner stdIn = new Scanner(System.in);		

		int num = stdIn.nextInt();

		int x_axis[] = new int[num];

		for (int i = 0; i < num; i++) {
			x_axis[i]	= stdIn.nextInt();
		}

		Arrays.sort(x_axis);

		int min = -1;
		int tmp = 0;
		boolean flag = false;
		for (int j = 0; j <= num - 2; j++) {
			if ( x_axis[j] == x_axis[j+1]) { continue; }
			if ( ! flag ) {
				min = Math.abs(x_axis[j] - x_axis[j+1]);	
				flag = true;
			} else {
				tmp = Math.abs(x_axis[j] - x_axis[j+1]);	
			}
			if (tmp <= min && min != -1) {
				min = tmp;
			} else {
				min = tmp;
		  }
		}
		if ( ! flag ) {
			System.out.println(0);
		} else {
			System.out.println(min);
		}

	}
}