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

# Design_by_JOKER

from math import *
from cmath import *
from itertools import *
from decimal import *  # su dung voi so thuc
from fractions import *  # su dung voi phan so
from sys import *

# getcontext().prec = x # lay x-1 chu so sau giay phay (thuoc decimal)
# Decimal('12.3') la 12.3 nhung Decimal(12.3) la 12.30000000012
# Fraction(a) # tra ra phan so bang a (Fraction('1.23') la 123/100 Fraction(1.23) la so khac (thuoc Fraction)
# a = complex(c, d) a = c + d(i) (c = a.real, d = a.imag)
# a.capitalize() bien ki tu dau cua a(string) thanh chu hoa, a.lower() bien a thanh chu thuong, tuong tu voi a.upper()
# a.swapcase() doi nguoc hoa thuong, a.title() bien chu hoa sau dau cach, a.replace('a', 'b', slg)
# a.join['a', 'b', 'c'] = 'a'a'b'a'c, a.strip('a') bo dau va cuoi ki tu 'a'(rstrip, lstrip)
# a.split('a', slg = -1) cat theo ki tu 'a' slg lan(rsplit(), lsplit()), a.count('aa', dau = 0, cuoi= len(a)) dem slg
# a.startswith('a', dau = 0, cuoi = len(a)) co bat dau bang 'a' ko(tuong tu endswith())
# a.index("aa") vi tri dau tien xuat hien (rfind())
# input = open(".inp", mode='r')  a = input.readline()
# out = open(".out", mode='w')# a.index(val)

for _ in range(1):
    a = [int(x) for x in input().split()]
    a.sort()
    print(['NO', 'YES'][a[0] +a[3] == a[1] + a[2] or a[3] == a[0] + a[1] + a[2]])