import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {

    // Complete the minimumDistances function below.
    static int minimumDistances(int[] a) {
        ArrayList<Integer> myList = new ArrayList<Integer>();
        for(int i=0;i<a.length-1;i++){
            for(int j=i+1;j<a.length;j++){
                if(a[i]==a[j]){
                    myList.add(Math.abs(i-j));
                }
            }
        }
        if(myList.size()==0) return -1;
        Collections.sort(myList);
        return myList.get(0);
    }

    private static final Scanner scanner = new Scanner(System.in);

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

        int n = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        int[] a = new int[n];

        String[] aItems = scanner.nextLine().split(" ");
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        for (int i = 0; i < n; i++) {
            int aItem = Integer.parseInt(aItems[i]);
            a[i] = aItem;
        }

        int result = minimumDistances(a);

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

        bufferedWriter.close();

        scanner.close();
    }
}

add MinimumDistances.java