#include <iostream>
#include <algorithm>

using namespace std;

int main(){
  int x, y;
  cin >> x >> y;
  
  if(abs(x - y) < 3){
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}
//Radhe Radhe
#include<bits/stdc++.h>
#define FASTIO_  ios_base:: sync_with_stdio(false); cin.tie(0); cout.tie(0);

#define ll long long
#define ld long double
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define en '\n'
#define itr(i,n)    for(ll i=0; i<n; i++)
#define itr_ab(i,a,b)    for(ll i=a; i<=b; i++)
#define itrV(i,n)    for(ll i=0; i<v.size(); i++)
#define fixed cout.setf(ios::fixed);
#define precise cout.precision(7);
#define Dont_Quit int main(void)
#define Avada_Kedavra return 0;
#define yes cout<<"Yes"<<'\n'
#define no cout<<"No"<<'\n'
using namespace std;




Dont_Quit
{
    FASTIO_
    ll  tc,n,i;
    string s,t;
    tc=1;
    bool ok=1;
    while(tc--)
    {
        ll x,y;
        cin>>x>>y;
        if(abs(x-y)>2)
            no;
        else
            yes;




    }

    Avada_Kedavra
}



