#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define endl '\n'
#define nitro std::ios_base::sync_with_stdio(false), std::cin.tie(NULL)
#define pi 3.141592653589793
#define mod 1000000007
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define sz(x) (int)x.size()
#define all(v) v.begin(), v.end()
#define debug(x) cerr<<GREEN<<#x": "<<(x)<<endl<<RESET
#define case_g(x) cout<<"Case #"<<x<<": "
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned long ul;
typedef std::vector<int> vi;
typedef std::vector<ll> vl;
typedef std::vector<bool> vb;
typedef std::pair<int, int> pii;
typedef std::pair<ll, ll> pll;
typedef std::pair<int, bool> pib;
typedef std::pair<ll, bool> plb;
typedef std::vector<pii> vii;
typedef std::vector<pll> vll;
typedef std::vector<pib> vib;
typedef std::vector<plb> vlb;
typedef std::vector<vi> vvi;
typedef std::vector<vl> vvl;
typedef std::vector<vb> vvb;
typedef std::unordered_map<int, int> umapii;
typedef std::unordered_map<ll, ll> umapll;
typedef std::unordered_map<int , bool> umapib;
typedef std::unordered_map<ll, bool> umaplb;
typedef std::map<int, int> mapii;
typedef std::map<ll, ll> mapll;
typedef std::map<int, bool> mapib;
typedef std::map<ll, bool> maplb;

typedef tree<pii, null_type, less<pii>, rb_tree_tag, tree_order_statistics_node_update> ranked_pairset;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ranked_set;
typedef tree<int, int, less<int>, rb_tree_tag, tree_order_statistics_node_update> ranked_map;

#define RED "\033[31m"
#define GREEN "\033[32m"
#define RESET "\033[0m"

void precompute() {
}

void solve() {
	vi a(3);
	
	cin >> a[0] >> a[1] >> a[2];
	
	sort(all(a));
	
	if( a[1] == a[0] ) cout << a[2] << endl;
	else if( a[1] == a[2] ) cout << a[0] << endl;
	else cout << 0 << endl;
}

int main() {
	nitro;
	
	int tc = 1;
	//cin >> tc;
	
	precompute();
	for(int i = 1; i <= tc; ++i) {
		//case_g(i);
		solve();
	}
	return 0;
}

#include<iostream>

using namespace std;

int a[4];

int main(){
    for(int i=0;i<4;++i) cin>>a[i];
    for(int i=0;i<1<<4;++i){
        int remain=0,tot=0;
        for(int j=0;j<4;++j){
            if(i>>j&1) tot+=a[j];
            else remain+=a[j];
        }
        if(remain==tot){
            puts("Yes");
            return 0;
        }
    }
    puts("No");
    return 0;
}