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

int main() {
  ios::sync_with_stdio(false); cin.tie(0);
  int x, y; cin >> x >> y;
  cout << (abs(x-y) < 3 ? "Yes" : "No");
  return 0;
}
#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pi;
typedef vector<vi> vii;

#define f first
#define s second
#define pb push_back
#define mp make_pair
#define loop(n) for(int i=0; i<n; i++)
#define rep(i, a, n) for(int i=a; i<n; i++)
#define file_read freopen("input.txt", "r", stdin); \
				  freopen("output.txt", "w", stdout);
#define tc int t; cin>>t; while(t--)
#define endl "\n"
#define usainbolt cin.tie(0) -> sync_with_stdio(0)




int main(void){
	usainbolt;
	//file_read

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

	int ans = abs(x-y);

	if(ans < 3){
		cout<<"Yes"<<endl;
	}
	else{
		cout<<"No"<<endl;
	}
	
}