44 58 90 53
 20 14 37 71
 4 2 4 2
 1 2 5 5
 1 2 8 9
 99 100 3 98
 92 69 83 97
 3 1 1 1
 18 88 18 18
 1 1 1 1
 69 7 44 30
 90 30 30 30
 1 2 3 5
 1 1 3 1
 6 3 6 6
 26 52 7 19
 6 4 8 6
 10 2 3 5
 34 11 84 39
 1 1 14 12
 3 2 1 1
 2 4 6 6
 1 1 2 1
 72 96 2 26
 97 95 91 27
 1 2 1 3
 1 1 2 3
 1 1 1 2
 1 1 10 20
 2 3 2 5
 1 2 10 7
 2 1 28 9
 4 4 4 8
 2 2 4 6
 72 52 62 62
 76 97 99 74
 100 100 99 100
 30 74 41 63
 5 10 1 6
 18 17 17 20
 2 4 1 1
 7 3 6 3
 1 1 4 5
 2 2 6 2
 1 2 6 3
 3 5 1 3
 70 100 10 86
 48 14 3 31
 2 6 3 2
 2 3 10 10
 4 4 12 4
 14 9 10 6
 100 98 99 97
 5 7 1 3
 1 1 4 2
 14 10 18 24
 1 100 100 1
 1 2 4 5
 1 2 3 4
 1 2 3 3
 4 4 4 5
 66 68 16 82
 1 2 3 2
 2 3 3 4
 100 100 100 100
 1 2 2 7
 3 14 36 53
 1 1 3 4

NO
 YES
 YES
 NO
 YES
 NO
 NO
 YES
 NO
 YES
 NO
 YES
 NO
 YES
 NO
 YES
 YES
 YES
 YES
 YES
 NO
 NO
 NO
 YES
 NO
 NO
 NO
 NO
 NO
 NO
 YES
 NO
 NO
 NO
 YES
 YES
 NO
 YES
 YES
 NO
 YES
 NO
 NO
 YES
 YES
 YES
 NO
 YES
 NO
 NO
 YES
 NO
 YES
 YES
 YES
 NO
 YES
 YES
 YES
 NO
 NO
 NO
 YES
 YES
 YES
 NO
 YES
 NO

import java.util.*;
import java.io.*;
import java.lang.*;

public final class cd203
{	
	public static void main(String args[])throws IOException
	{	
	try{
	 //takign input through IO
	 InputReader in = new InputReader(System.in);
	 OutputWriter out = new OutputWriter(System.out);
	 int arr[] = IOUtils.readIntArray(in,4),flag =0,i,sum=0;
	 ArrayList<Integer> list = new ArrayList<>();
	 for(i=0;i<arr.length;i++)
	 {
		 sum+=arr[i];
		 list.add(arr[i]);
	 }
	 if(sum%2==0)
	 {
		 for(i=0;i<arr.length;i++)
		 {
			 if(list.contains(sum/2-arr[i]))
			 {
				 flag =1;
				 break;
			 }
		 }
		 if(flag!=1)
			 out.printLine("NO");
		 else
			 out.printLine("YES");
		 
	 }else
	 {
		 out.printLine("NO");
	 }
	 out.close();
	}
	catch(Exception e){
		e.printStackTrace();
	}	
}

}

class InputReader
{
    private InputStream stream;
    private byte[] buf = new byte[1024];
    private int curChar;
    private int numChars;
    private SpaceCharFilter filter;
 
    public InputReader(InputStream stream)
    {
        this.stream = stream;
    }
 
    public int read()
    {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars)
        {
            curChar = 0;
            try
            {
                numChars = stream.read(buf);
            }
			catch (IOException e)
            {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }
 
    public int readInt()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
        {
            sgn = -1;
            c = read();
        }
        int res = 0;
        do
        {
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }
 
	public String readString()
    {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        StringBuilder res = new StringBuilder();
        do
        {
            res.appendCodePoint(c);
            c = read();
        } while (!isSpaceChar(c));
        return res.toString();
    }
    
	public double readDouble() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
		{
            sgn = -1;
            c = read();
        }
        double res = 0;
        while (!isSpaceChar(c) && c != '.')
		{
            if (c == 'e' || c == 'E')
                return res * Math.pow(10, readInt());
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        }
        if (c == '.')
		{
            c = read();
            double m = 1;
            while (!isSpaceChar(c))
			{
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, readInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                m /= 10;
                res += (c - '0') * m;
                c = read();
            }
        }
        return res * sgn;
    }
	
    public long readLong()
	{
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-')
		{
            sgn = -1;
            c = read();
        }
        long res = 0;
        do
		{
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }
	
    public boolean isSpaceChar(int c)
    {
        if (filter != null)
            return filter.isSpaceChar(c);
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }
 
    public String next()
    {
        return readString();
    }
 
    public interface SpaceCharFilter
    {
        public boolean isSpaceChar(int ch);
    }
}
 
class OutputWriter
{
    private final PrintWriter writer;
 
    public OutputWriter(OutputStream outputStream)
    {
        writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
    }
 
    public OutputWriter(Writer writer)
    {
        this.writer = new PrintWriter(writer);
    }
 
    public void print(Object... objects)
    {
        for (int i = 0; i < objects.length; i++)
        {
            if (i != 0)
                writer.print(' ');
            writer.print(objects[i]);
        }
    }
 
    public void printLine(Object... objects)
    {
        print(objects);
        writer.println();
    }
 
    public void close()
    {
        writer.close();
    }
 
    public void flush()
    {
        writer.flush();
    }
 
}
 
/*
>>USAGE
 
//initialize
        InputReader in = new InputReader(System.in);
        OutputWriter out = new OutputWriter(System.out);
 
//read int
   int i = in.readInt();
//read string
   String s = in.readString();
//read int array of size N
   int[] x = IOUtils.readIntArray(in,N);
//printline
   out.printLine("X");
 
 
//flush output
   out.flush();
 
//remember to close the
//outputstream, at the end
   out.close();
*/
 
 
class IOUtils
	{
		public static int[] readIntArray(InputReader in, int size)
		{
            int[] array = new int[size];
            for (int i = 0; i < size; i++)
                array[i] = in.readInt();
            return array;
		}
	}