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 tmp_min = 1000001;
		int result1, result2;
		for (int i = 1; i < num - 1; i++) {
			result1 = Math.abs( x_axis[i] - x_axis[i+1]);	
			if ( result1 != 0 ) { 
				if ( result1 < tmp_min ) { tmp_min = result1; }
			}
			result2 = Math.abs( x_axis[i] - x_axis[i-1]);
			if ( result2 != 0 && result2 < tmp_min ) { 
				tmp_min = result2;
			}
			//tmp_min = (result1 < result2) ? result1 : result2;
		}
		if ( tmp_min == 1000001 ) {
			System.out.println(0);
		} else {
			System.out.println(tmp_min);
		}
	}
}