#pragma GCC optimize("Ofast") 
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define mp make_pair
#define all(a) a.begin(),a.end()
#define sz(a) (int)(a.size())
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define MOD (ll)(1e9+7)
#define INF (ll)(1e18)
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll A,ll B) {if(!B)return A;return gcd(B,A%B);}
int main()
{
   ll a[5];
  bool ok = 0;
  cin>>a[0]>>a[1]>>a[2]>>a[3];
  a[4] = 0;
  ll sum = a[0]+a[1]+a[2]+a[3];
  for(int i=0;i<5;i++){
	  for(int j=0;j<5;j++){
		  if(i == j)continue;
		  for(int k=0;k<5;k++){
			  if(j == k || i == k)continue;
			  if(sum-a[i]-a[j]-a[k] == a[i]+a[j]+a[k])ok = 1;
			  
		  }
	  } 
	  }
	  if(ok)cout<<"Yes";
	  else cout<<"No";
}

#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define ll long long
// #include <ext/pb_ds/assoc_container.hpp> 
// #include <ext/pb_ds/tree_policy.hpp> 
// using namespace __gnu_pbds; 
  
// #define ordered_set tree<ll, null_type,less<ll>, rb_tree_tag,tree_order_statistics_node_update> 
  
int32_t main(){ 
    ios_base::sync_with_stdio(false); 
    cin.tie(NULL);
    ll t = 1;
    // cin >> t;
    while(t--)
    {
        ll a, b, c, d;
        cin >> a >> b >> c >> d;
        cout << b-c;
    }
    return 0;
}
