#include <iostream>
using namespace std;
int main() {

int x ,y ;
cin >> x >> y ;

if (x != y){
  if (x < y){
    if (x+3 > y){
      cout<< "Yes"<<endl;
    } else if (x+3 <= y){
      cout << "No" <<endl;
    }
  }
  else if(y < x){
    if (y+3 > x){
      cout<< "Yes"<<endl;
    } else if (y+3 <= x){
      cout << "No" <<endl;
    }    
  }
}    



}
#include<bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

int main(){
  int X,Y; cin>>X>>Y;
  if(abs(X-Y)<=2) cout<<"Yes"<<endl;
  else cout<<"No"<<endl;
  return 0;
}
