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

#include <bits/stdc++.h>
using namespace std;
using std::bitset;
const long long maxn = 1e6 + 5;
const long long mod = 998244353;
const long long INF = 0x3f3f3f3f3f3f3f3f;
const long double PI = acos(-1.0);
const long double eps = 1e-5;
inline long long read() {
  long long ans = 0, flag = 1;
  char c;
  c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-') flag = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    ans = ans * 10 + (long long)(c - '0');
    c = getchar();
  }
  return ans * flag;
}
long long quickpow(long long x, long long y, long long mod) {
  long long ans = 1;
  while (y) {
    if (y & 1) ans = ans * x % mod;
    x = x * x % mod;
    y >>= 1;
  }
  return ans;
}
int main() {
  int a1, a2, a3, a4;
  while (cin >> a1 >> a2 >> a3 >> a4) {
    if (a1 + a2 == a3 + a4)
      cout << "YES" << endl;
    else if (a1 + a3 == a2 + a4)
      cout << "YES" << endl;
    else if (a1 + a4 == a2 + a3)
      cout << "YES" << endl;
    else if (a1 == a2 + a3 + a4)
      cout << "YES" << endl;
    else if (a2 == a1 + a3 + a4)
      cout << "YES" << endl;
    else if (a3 == a2 + a1 + a4)
      cout << "YES" << endl;
    else if (a4 == a2 + a3 + a1)
      cout << "YES" << endl;
    else
      cout << "NO" << endl;
  }
  return 0;
}
