#include <iostream>
 
using namespace std;
 
int a, b;
 
void swap(int &a, int &b) {
    if (a > b) {
        int temp = a;
        a = b;
        b = temp;
    }
}
void solve() {
    cin >> a >> b;
    
    swap(a, b);
    int diff = b - a;
    
    if(diff >= 3) cout << "No" <<endl;
    else cout << "Yes" << endl;
}
 
int main() {
    ios_base::sync_with_stdio(0);
 
    solve();
}

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

#define rep(i,n) for(ll i=0;i<ll(n);i++)

int main(){
  int X,Y;
  cin>>X>>Y;
  if(X>Y){
    if((X-Y)<3){
      cout<<"Yes";
    }
    else{
      cout<<"No";
    }
  }
  else{
    if((Y-X)<3){
      cout<<"Yes";
    }
    else{
      cout<<"No";
    }
  }
  return 0;
}