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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;

import java.lang.management.MemoryType;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.util.*;
import java.util.function.Function;


public class Main {
    static final int INF = Integer.MAX_VALUE;

    static int mergeSort(int[] a,int [] c, int begin, int end)
    {
        int inversion=0;
        if(begin < end)
        {
            inversion=0;
            int mid = (begin + end) >>1;
            inversion+= mergeSort(a,c, begin, mid);
            inversion+=mergeSort(a, c,mid + 1, end);
            inversion+=merge(a,c, begin, mid, end);
        }
        return inversion;
    }


    static int  merge(int[] a,int[]c, int b, int mid, int e)
    {
        int n1 = mid - b + 1;
        int n2 = e - mid;
        int[] L = new int[n1+1], R = new int[n2+1];
        int[] L1 = new int[n1+1], R1 = new int[n2+1];


        //inversion
        int inversion=0;

        for(int i = 0; i < n1; i++) {
            L[i] = a[b + i];
            L1[i] = c[b + i];
            //  L2[i] = w[b + i];
        }
        for(int i = 0; i < n2; i++)  {
            R[i] = a[mid + 1 + i];
            R1[i] = c[mid + 1 + i];
            //R2[i] = w[mid + 1 + i];
        }
        L[n1] = R[n2] = INF;

        for(int k = b, i = 0, j = 0; k <= e; k++)
            if(L[i] <= R[j]){
                a[k] = L[i];
                c[k] = L1[i];
                ++i;
                //  w[k]=L2[i++];
            }

            else
            {
                a[k] = R[j];
                c[k] = R1[j];
                //w[k] = R2[j++];
                ++j;

                inversion=inversion+(n1-i);

            }
        return inversion;

    }






   static  long[][]mem;
    static int []a,b;
    static long solve(int ind, int add) {
        if (ind == a.length-1)return 0;
        if (mem[ind][add]!=-1)return mem[ind][add];

        long ret = Long.MAX_VALUE;
        for (int i = 0; i <= 2; i++) {
            if ((a[ind] + add) != (a[ind + 1] + i)) {
                ret = Math.min(ret, solve(ind + 1, i) + b[ind + 1] * i);
            }
        }
        return mem[ind][add]=ret;
    }



    public static void main (String[]args) throws IOException {
        Scanner in = new Scanner(System.in);
        try(PrintWriter or = new PrintWriter(System.out)) {


           int[] a= new int[4];
           int ans=0;
            for (int i = 0; i < 4; i++) {
                ans+=(a[i]=in.nextInt());
            }

            for (int i = 0; i < 2<<4; i++) {
                int b=0;
                for (int j = 0; j < 4; j++) {
                    if ((i&(1<<j))>0)b+=a[j];
                }
                if (ans-b==b){
                    or.println("YES");
                    return;
                }
            }
            or.println("NO");





        }
    }




    static int getlen(int r,int l,int a){
        return (r-l+1+1)/(a+1);
    }






    static class Scanner {

        StringTokenizer st;
        BufferedReader br;

        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens()) {
                st = new StringTokenizer(br.readLine());
            }
            return st.nextToken();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if (x.charAt(0) == '-') {
                neg = true;
                start++;
            }
            for (int i = start; i < x.length(); i++) {
                if (x.charAt(i) == '.') {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                } else {
                    sb.append(x.charAt(i));
                    if (dec) {
                        f *= 10;
                    }
                }
            }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg ? -1 : 1);
        }

        public boolean ready() throws IOException {
            return br.ready();
        }

    }
}

class Pair  {
    int first, second;

    public Pair(int first, int second) {
        this.first = first;
        this.second = second;
    }




}

class Tempo {

    int num;
    int index;

    public Tempo(int num, int index) {
        this.num = num;
        this.index = index;
    }
}