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;
clock_t tp = clock();
long long int power1(long long int x, long long int y) {
  long long int res = 1;
  x = x;
  while (y > 0) {
    if (y & 1) res = (res * x);
    y = y >> 1;
    x = (x * x);
  }
  return res;
}
long long int gcd(long long int a, long long int b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
long long int ncr(long long int n, long long int r) {
  if (n < r) return 0;
  long long int p = 1, k = 1;
  if (n - r < r) r = n - r;
  if (r != 0) {
    while (r) {
      p *= n;
      k *= r;
      long long int g = gcd(p, k);
      p /= g;
      k /= g;
      n--;
      r--;
    }
  } else
    p = 1;
  return p;
}
long long int lcm(long long int a, long long int b) {
  return (a / gcd(a, b) * b);
}
bool compare_incresing(pair<long long int, long long int> l1,
                       pair<long long int, long long int> l2) {
  if (l1.first != l2.first)
    return (l1.first < l2.first);
  else
    return (l1.second < l2.second);
}
long long int n, e[100005][2], par[15], a[100005];
vector<long long int> ed[100005];
long long int parent(long long int n) {
  if (par[n] > 0) return par[n];
  long long int x = 0;
  for (auto it : ed[n]) {
    x = it;
    if (parent(x) != -1) break;
  }
  return par[n] = x;
}
long long int find(long long int n, long long int an) {
  long long int cnt = 0;
  for (auto it : ed[n]) {
    if (it == parent(n)) continue;
    cnt += find(it, an);
  }
  if (an > a[n - 1]) cnt += a[n - 1];
  return cnt;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int tt = 1;
  while (tt--) {
    int a[4];
    for (long long int i = 0; i < 4; i++) cin >> a[i];
    for (int i = 0; i < 16; i++) {
      int x = i, sum1 = 0, sum2 = 0, ii = 0;
      while (x) {
        if (x % 2)
          sum1 += a[ii++];
        else
          sum2 += a[ii++];
        x /= 2;
      }
      while (ii < 4) sum2 += a[ii++];
      if (sum1 == sum2) {
        cout << "YES";
        return 0;
      }
    }
    cout << "NO";
  }
  return 0;
}
