import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
public class Test{
    public static void main(String[] args) throws IOException{
        BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));
        int N = Integer.parseInt(buf.readLine());
        String[] s = buf.readLine().split(" ");
        int X[] = new int[N];
        X[0]=Integer.parseInt(s[0]);
        for(int i=1;i<N;i++) {
        	X[i]=Integer.parseInt(s[i]);
        }
        Arrays.sort(X);
        int min=1000001;
        for(int i=1;i<N;i++) {
        	if(Math.abs(X[i-1]-X[i])<min && X[i-1]!=X[i]) {
        		min=Math.abs(X[i-1]-X[i]);
        	}
        }
        if(min==1000001)System.out.println(0);
        else System.out.println(min);
    }
}