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.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.util.Set;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) throws IOException  {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA {
        public void solve(int testNumber, InputReader in, OutputWriter out) throws IOException {
            int[] a = in.nextIntArray(4);
            List sums = new ArrayList();
            for (int i = 0; i < a.length; i++) {
                int elem = a[i];
                sums.add(elem);

                for (int j = i + 1; j < a.length - 1; j++) {
                    int sum = elem + a[j];
                    sums.add(sum);
                }
            }
            Set set = new HashSet(sums);
            if (sums.size() == set.size())
                out.print("YES");
            else
                out.print("NO");
        }

    }

    static class InputReader {
        private static final int DEFAULT_BUFFER_SIZE = 1 << 16;
        private static final InputStream DEFAULT_STREAM = System.in;
        private int c;
        private byte[] buf;
        private int bufferSize;
        private int bufIndex;
        private int numBytesRead;
        private InputStream stream;
        private static final byte EOF = -1;
        private static final byte SPACE = 32;
        private static final byte DASH = 45;
        private char[] charBuffer;
        private static byte[] bytes = new byte[58];
        private static int[] ints = new int[58];
        private static char[] chars = new char[128];

        static {
            char ch = ' ';
            int value = 0;
            byte _byte = 0;
            for (int i = 48; i < 58; i++) bytes[i] = _byte++;
            for (int i = 48; i < 58; i++) ints[i] = value++;
            for (int i = 32; i < 128; i++) chars[i] = ch++;
        }

        public InputReader() {
            this(DEFAULT_STREAM, DEFAULT_BUFFER_SIZE);
        }

        public InputReader(int bufferSize) {
            this(DEFAULT_STREAM, bufferSize);
        }

        public InputReader(InputStream stream) {
            this(stream, DEFAULT_BUFFER_SIZE);
        }

        public InputReader(InputStream stream, int bufferSize) {
            if (stream == null || bufferSize <= 0)
                throw new IllegalArgumentException();
            buf = new byte[bufferSize];
            charBuffer = new char[128];
            this.bufferSize = bufferSize;
            this.stream = stream;
        }

        private int readJunk(int token) throws IOException {

            if (numBytesRead == EOF) return EOF;

            // Seek to the first valid position index
            do {

                while (bufIndex < numBytesRead) {
                    if (buf[bufIndex] > token) return 0;
                    bufIndex++;
                }

                // reload buffer
                numBytesRead = stream.read(buf);
                if (numBytesRead == EOF) return EOF;
                bufIndex = 0;

            } while (true);

        }

        public int nextInt() throws IOException {

            if (readJunk(DASH - 1) == EOF) throw new IOException();
            int sgn = 1, res = 0;

            c = buf[bufIndex];
            if (c == DASH) {
                sgn = -1;
                bufIndex++;
            }

            do {

                while (bufIndex < numBytesRead) {
                    if (buf[bufIndex] > SPACE) {
                        res = (res << 3) + (res << 1);
                        res += ints[buf[bufIndex++]];
                    } else {
                        bufIndex++;
                        return res * sgn;
                    }
                }

                // Reload buffer
                numBytesRead = stream.read(buf);
                if (numBytesRead == EOF) return res * sgn;
                bufIndex = 0;

            } while (true);

        }

        public int[] nextIntArray(int n) throws IOException {
            int[] ar = new int[n];
            for (int i = 0; i < n; i++) ar[i] = nextInt();
            return ar;
        }

    }

    static 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 close() {
            writer.close();
        }

    }
}

