#include<bits/stdc++.h>
int main(){
  int a,b,c,d;
  scanf("%d%d%d",&a,&b,&c);
  d=a+b+c;
  puts(d==a*3||d==b*3||d==c*3?"Yes":"No");
}
#include<bits/stdc++.h>
using ll= long long;
#define REP(i,n) for(ll i=0;i<ll(n);i++)
#define RREP(i,n) for(ll i=1;i<ll(n+1);i++)
#define FOR(i,a,b) for(ll i=a;i<=ll(b);i++)
#define ALL(x) x.begin(),x.end()

#define INF (int)1e9 //10^9:∞
#define LLINF (long long)1e12
#define MOD (int)1e9+7 //10^9+7:合同式の法
#define PI 3.141592653589
#define PB push_back
#define Fir first
#define Sec second
#define __MAGIC__ ios::sync_with_stdio(false);cin.tie(nullptr);

#define YESNO(T) if(T){cout<<"YES"<<endl;}else{cout<<"NO"<<endl;}
#define yesno(T) if(T){cout<<"yes"<<endl;}else{cout<<"no"<<endl;}
#define YesNo(T) if(T){cout<<"Yes"<<endl;}else{cout<<"No"<<endl;}

#define Graph vector<vector<int>>
#define PII pair<int,int>
#define VI vector<int>
#define VVI vector<vector<int>>  // Graph
#define VPII vector<pair<int,int>>
#define VPLL vector<pair<ll, ll>>

#define DDD fixed<<setprecision(17)

using namespace std;
/*..................DEFINE GLOBAL VARIABLES...................*/


/*.....................DEFINE FUNCTIONS ......................*/
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

/*.........................memo0

...........................*/

/*.........................memo1

...........................*/

/*.........................memo2

...........................*/
signed main() {
    __MAGIC__
    int a, b, c;
    cin >> a >> b >> c;
    int m1 = 0, m2 = 0, m3 = 0;
    chmax(m1, a);
    chmax(m1, b);
    chmax(m1, c);
    bool isB = false;
    if(m1 != a) {
        chmax(m2, a);
        isB = true;
    }
    if (m1 != b) {
        chmax(m2, b);
        isB = true;
    }
    if (m1 != c) {
        chmax(m2, c);
        isB = true;
    }
    if (!isB) {
        m2 = m1;
    }
    bool isC = false;
    if(m1 != a && m2 != a) {
        chmax(m3, a);
        isC = true;
    }
    if (m1 != b && m2 != b) {
        chmax(m3, b);
        isC = true;
    }
    if (m1 != c && m2 != c) {
        chmax(m3, c);
        isC = true;
    }
    if (!isC) {
        m3 = m2;
    }
    YesNo(m3-m2 == m2-m1);
    return 0;
}