import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

class Result {

    /*
     * Complete the 'minimumLoss' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts LONG_INTEGER_ARRAY price as parameter.
     */

    public static long minimumLoss(List<Long> price) {

        TreeSet<Long> priceSet = new TreeSet<>();
        long min = Long.MAX_VALUE;
        for (int i = 0; i < price.size(); i++) {
            Long higher = priceSet.higher(price.get(i));
            if (higher != null) {
                min = Math.min(higher - price.get(i), min);     
            }
            priceSet.add(price.get(i));
        }
        
        return min;
    }

}

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int n = Integer.parseInt(bufferedReader.readLine().trim());

        List<Long> price = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
            .map(Long::parseLong)
            .collect(toList());

        long result = Result.minimumLoss(price);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}