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

int main() {
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif

	int x, y;
	cin >> x >> y;
	int z = (x > y ? y - x : x - y) + 3;
	if (z > 0) cout << "Yes";
	else cout << "No";
}
#include<bits/stdc++.h>
using namespace std;

#define f(t) ll t; cin>>t; while(t--)
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define vec vector<ll>
#define vecpair vector<pair<ll,ll>>

using ll = long long;
using ld = long double;

const int N = 2e5 + 5;

int main(){
    IOS;
        int x,y;
        cin>>x>>y;
        if(abs(x-y)>=3){
            cout<<"No"<<endl;
        }
        else{
            cout<<"Yes"<<endl;
        }
}