using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;

namespace No507
{
    public class Program
    {
        int N;
        int M;
        int K;
        int[] A;

        void Solve(StreamScanner ss, StreamWriter sw)
        {
            //---------------------------------
            N = ss.Next(int.Parse);
            M = ss.Next(int.Parse);
            K = ss.Next(int.Parse);
            A = ss.Next(int.Parse, N - 1).OrderByDescending(x => x).ToArray();

            var ret = BinarySearch.LowerBound(CountStrongPairs, M, 0, A.Length) - 1;
            sw.WriteLine(ret == -1 ? ret : A[ret]);
            //---------------------------------
        }

        int CountStrongPairs(long index)
        {
            var ret = 0;

            for (int left = 0, right = A.Length - 1; left < A.Length && left < right; left++)
            {
                if (left == index) continue;

                for (; left < right; right--)
                {
                    if (right == index || A[right] + A[left] <= A[index] + K) continue;
                    right--;
                    ret++;
                    break;
                }
            }

            return ret;
        }

        static void Main()
        {
            var ss = new StreamScanner(new StreamReader(Console.OpenStandardInput()));
            var sw = new StreamWriter(Console.OpenStandardOutput()) {AutoFlush = false};
            new Program().Solve(ss, sw);
            sw.Flush();
        }

        static readonly Func<string, string> String = s => s;
    }

    public static partial class BinarySearch
    {
        static long BoundToTheRight(Func<long, bool> pred, long left, long right)
        {
            if (left > right) throw new ArgumentException("left must <= right");

            while (true)
            {
                if (left == right) return right;
                var mid = (left + right - 1) / 2;
                if (pred(mid)) right = mid;
                else left = mid + 1;
            }
        }

        public static long LowerBound<T>(Func<long, T> func, T value, long left, long right) where T : IComparable<T>
        {
            return BoundToTheRight(x => func(x).CompareTo(value) >= 0, left, right);
        }

        public static long UpperBound<T>(Func<long, T> func, T value, long left, long right) where T : IComparable<T>
        {
            return BoundToTheRight(x => func(x).CompareTo(value) > 0, left, right);
        }

        public static int LowerBound<T>(this T[] source, T value) where T : IComparable<T>
        {
            return (int)LowerBound(x => source[x], value, 0, source.Length);
        }

        public static int UpperBound<T>(this T[] source, T value) where T : IComparable<T>
        {
            return (int)UpperBound(x => source[x], value, 0, source.Length);
        }

        public static int Range<T>(this T[] source, T vLeft, T vRight) where T : IComparable<T>
        {
            return source.UpperBound(vRight) - source.LowerBound(vLeft);
        }
    }

    public class StreamScanner
    {
        static readonly char[] Sep = {' '};
        readonly Queue<string> buffer = new Queue<string>();
        readonly TextReader textReader;

        public StreamScanner(TextReader textReader)
        {
            this.textReader = textReader;
        }

        public T Next<T>(Func<string, T> parser)
        {
            if (buffer.Count != 0) return parser(buffer.Dequeue());
            var nextStrings = textReader.ReadLine().Split(Sep, StringSplitOptions.RemoveEmptyEntries);
            foreach (var nextString in nextStrings) buffer.Enqueue(nextString);
            return Next(parser);
        }

        public T[] Next<T>(Func<string, T> parser, int x)
        {
            var ret = new T[x];
            for (var i = 0; i < x; ++i) ret[i] = Next(parser);
            return ret;
        }

        public T[][] Next<T>(Func<string, T> parser, int x, int y)
        {
            var ret = new T[y][];
            for (var i = 0; i < y; ++i) ret[i] = Next(parser, x);
            return ret;
        }
    }
}