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;
const int maxn = 1e5 + 200;
const int inf = 0x3f3f3f3f;
const double eps = 1e-7;
const double pi = acos(-1.0);
const int mod = 1e9 + 7;
inline int lowbit(int x) { return x & (-x); }
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
void ex_gcd(long long a, long long b, long long &d, long long &x,
            long long &y) {
  if (!b) {
    d = a, x = 1, y = 0;
  } else {
    ex_gcd(b, a % b, d, y, x);
    y -= x * (a / b);
  }
}
inline long long qpow(long long a, long long b, long long MOD = mod) {
  long long res = 1;
  a %= MOD;
  while (b > 0) {
    if (b & 1) res = res * a % MOD;
    a = a * a % MOD;
    b >>= 1;
  }
  return res;
}
inline long long inv(long long x, long long p) { return qpow(x, p - 2, p); }
inline long long Jos(long long n, long long k, long long s = 1) {
  long long res = 0;
  for (int i = 1; i <= n + 1; ++i) res = (res + k) % i;
  return (res + s) % n;
}
inline long long read() {
  long long f = 1;
  long long x = 0;
  char ch = getchar();
  while (ch > '9' | ch < '0') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9')
    x = (x << 3) + (x << 1) + ch - '0', ch = getchar();
  return x * f;
}
int dir[4][2] = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
long long a[10];
long long flag = 0;
void dfs(int pos, long long L, long long R) {
  if (flag) return;
  if (pos > 5) {
    if (L == R) cout << "YES" << endl, flag = 1;
    return;
  }
  dfs(pos + 1, L + a[pos], R);
  dfs(pos + 1, L, R + a[pos]);
}
int main() {
  while (cin >> a[1] >> a[2] >> a[3] >> a[4]) {
    flag = 0;
    dfs(1, 0, 0);
    if (!flag) cout << "NO" << endl;
  }
  return 0;
}
