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

//package com.company;

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

public class Main {

    private static boolean back(int v[], int sum1, int sum2, int j)
    {
        if(j == 4)
        {
            if(sum1 == sum2)
                return true;
            return false;
        }
        else
        {
            sum1 += v[j];
            // apel recursiv
            boolean b = back(v, sum1, sum2, j+1);
            sum1 -= v[j];

            sum2 += v[j];
            // apel recursiv
            boolean b2 = back(v, sum1, sum2, j+1);
            sum2 -= v[j];

            return b || b2;
        }
    }

    public static void main(String[] args) throws IOException {
        InputStreamReader read = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(read);

        String s = bufferedReader.readLine();
        String ss[] = s.split(" ");

        int v[] = new int[4];
        for(int i = 0; i < 4; i++)
            v[i] = Integer.parseInt(ss[i]);

        if(back(v, 0, 0, 0) == true)
            System.out.println("YES");
        else
            System.out.println("NO");
    }
}
