#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
    int a[4];
    for(int i=0;i<4;i++)cin>>a[i];
    sort(a,a+4);
    if(a[3]-a[0]==3)cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
    return 0;
}