import java.util.Scanner;

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

		Scanner stdIn = new Scanner(System.in);		

		int num = stdIn.nextInt();

		int vc[] = new int[num];

		for (int i = 0; i < num; i++) {
			vc[i] = stdIn.nextInt();
		}
		System.out.println(vc_Length(vc, num));
	}

	public static int vc_Length(int vc[], int num) {

		int tmp = 1000000;
		for (int i = 0; i < num; i++) {
			for (int k = 0; k < num; k++) {
				if (i == k) { continue; }
				if (vc[i] == vc[k]) { continue; }
				if (tmp > Math.abs(vc[i] - vc[k])) {
					tmp = Math.abs(vc[i] - vc[k]);
				} else {
					continue;
				}
			}
		}
		return tmp;
	}
}