#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;
typedef pair<ll, ll> pll;
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, a, b) for(int i = a; i >= b; i--)
#define ms memset
#define pb push_back
#define F first
#define S second
ll MOD = 1000000007;
ll INF = 1000000000;
 
ll power(ll base, ll n){
	if (n == 0) return 1;
	if (n == 1) return base;
	ll halfn = power(base, n/2);
	if (n % 2 == 0) return (halfn * halfn) % MOD;
	return (((halfn * halfn) % MOD) * base) % MOD;
}
 
ll inverse(ll n){
	return power(n, MOD-2);
}
 
ll add(ll a, ll b){
	return (a+b) % MOD;
}
 
ll mul(ll a, ll b){
	return (a*b) % MOD;
}
 
ll gcd(ll a, ll b){
	if (a == 0) return b;
	if (a == 1) return 1;
	return gcd(b%a, a);
}
 
int main(){
    ios::sync_with_stdio(false);
    int a1, a2, a3; cin >> a1 >> a2 >> a3;
    int a = min(a1, min(a2, a3)), b = max(a1, max(a2, a3));
    if (3 * (a+b) == 2*(a1 + a2 + a3)){
    	cout << "Yes\n";
	}else{
		cout << "No\n";
	}
	return 0;
}

//#include <bits/stdc++.h>
using namespace std;
#include <iostream>
 
 
int main() {

int A1,A2,A3;
cin>>A1>>A2>>A3;
if( A3-A2==A2-A1 || A3-A1==A1-A2 ||A2-A1==A1-A3 ||A2-A3==A3-A1 ||A1-A2==A2-A3 ||A1-A3==A3-A2 )
{
    cout<<"Yes"<<endl;
}
else
{
     cout<<"No"<<endl;
}
return 0;
}
