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;
long long a[3000005], has[3000005], visited[2000005], dist[1000005];
long long pr[3000010];
long long addmod(long long n, long long m) {
  return ((n % 1000000007) + (m % 1000000007)) % 1000000007;
}
long long multmod(long long n, long long m) {
  return ((n % 1000000007) * (m % 1000000007)) % 1000000007;
}
long long submod(long long n, long long m) {
  return ((n % 1000000007) - (m % 1000000007) + 1000000007) % 1000000007;
}
void prime() {
  pr[0] = 1;
  pr[1] = 1;
  for (long long i = 2; i <= sqrt(3000010); i++) {
    for (long long j = 2 * i; j <= 3000010; j += i) {
      pr[j] = 1;
    }
  }
}
long long cntDiv(long long n) {
  long long cnt = 0;
  for (long long i = 1; i <= sqrt(n); i++) {
    if (n % i == 0) {
      if (n / i == i)
        cnt++;
      else
        cnt += 2;
    }
  }
  return cnt;
}
long long gcd(long long a, long long b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
long long has1[3000011], b[1000005], temp1[1000005];
vector<long long> mat[10001];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long x, y, z, w;
  cin >> x >> y >> z >> w;
  if (x + y == z + w || x + z == y + w || x + w == y + z || x == y + z + w ||
      y == x + z + w || z == x + y + w || w == x + y + z)
    cout << "YES";
  else
    cout << "NO";
  return 0;
}
