#include<bits/stdc++.h>
using namespace std;
#define Y cout<<"YES"<<endl;
#define N cout<<"NO"<<endl;
#define tc int t; cin>>t; while(t--)
#define eki int n; cin>>n;
#define loop for(int i=0; i<n; i++)
#define mem(a,b) memset(a, b, sizeof(a) )
const int mx=1e4+123;

 
 int main(){
     int a, b, c;
     cin>>a>>b>>c;
     if((a+c-2*b)==0 || (b+c-2*a)==0 || (a+b-2*c)==0)
     cout<<"Yes"<<endl;
     else cout<<"No"<<endl;
 }
    
        
























































/*بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيم*/
#include <iostream>
using namespace std;
int main()
{
  int arr[3];
  for(int i=0; i<3; i++)
  {
    cin>>arr[i];
  }
  if(arr[0] == arr[1] && arr[1] == arr[2]){
    cout<<"Yes"<<endl;
    return 0;
  }
  if((arr[0]+arr[1] == 2*arr[2]) || (arr[0]+arr[2] == 2*arr[1]) || (arr[1]+arr[2] == 2*arr[0]))
  cout<<"Yes"<<endl;
  else
  cout<<"No"<<endl;

  return 0;
}
