#include <bits/stdc++.h>


using namespace std;
typedef long long ll;

#define REP(i,n) for(ll i=0; i<ll(n); i++)
#define FOR(i,m,n) for(ll i=ll(m); i<ll(n); i++)
#define ALL(obj) (obj).begin(),(obj).end()
#define VI vector<int>
#define VP vector<pair<int,int>>
#define VPP vector<pair<int,pair<int,int>>>
#define VLL vector<long long>
#define VVI vector<vector<int>>
#define VVLL vector<vector<long long>>
#define VC vector<char>
#define VS vector<string>
#define VVC vector<vector<char>>
#define VB vector<bool>
#define VVB vector<vector<bool>>
#define fore(i,a) for(auto &i:a)
typedef pair <int, int> P;
template<typename T> using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;

const int  INF = 1 << 29;
const ll INFL = 1LL << 60;
const ll mod = 1000000007;



int main() {
	VI v(4);
	REP(i, 4)cin >> v[i];

	sort(ALL(v));
	v[0] += 3;
	v[1] += 2;
	v[2] += 1;

	if (v[0] == v[1] && v[1] == v[2] && v[2] == v[3]) {
		cout << "Yes" << endl;
	}
	else cout << "No" << endl;


}