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 math
def moving_shift(s, shift):
    ans=''
    for i in range(len(s)):
        if 65<=ord(s[i])<=90 or 97<=ord(s[i])<=122:
            if s[i].islower():
                x=chr((((ord(s[i])+shift+i)-97)%26)+97)
                ans+=x
            else:
                x=chr((((ord(s[i])+shift+i)-65)%26)+65)
                ans+=x
        else:
            ans+=s[i]
    a=[0,0,0,0,0]
    integer=math.ceil(len(s)/5)

def demoving_shift(s, shift):
    pass

'''
import pygame
pygame.init()
screen = pygame.display.set_mode((400,400))
run=True
while run:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run=False
    screen.fill((255,255,255))
    pygame.draw.rect(screen,(0,0,0),(100,100,-20,-20))
    pygame.display.update()
'''
a = list(map(int,input().split()))
for i in range(4):
    for j in range(4):
        if a[i]==a[j]:
            continue
        for k in range(4):
            if a[k]==a[j] or a[k]==a[i]:
                continue
            for l in range(4):
                if a[l]==a[j] or a[l]==a[i] or a[l]==a[k]:
                    continue
                if a[i]+a[j]==a[k]+a[l]:
                    print("YES")
                    exit()
print("NO")


