#include <iostream>
#include <algorithm>
using namespace std;
 
int main()
{
	int a, b;
  	cin >> a >> b;
  	cout << (max(a,b)-min(a,b) < 3 ? "Yes" : "No") << endl;
}
#include<iostream>
#include<string>
#include<cstdio>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<vector>
#include<utility>
#include<queue>
#include<stack>
#include<set>
#include<map>
#include<bitset>
#include<iomanip>
#include<list>
#include<deque>
using namespace std;
//#define MODE 1
#ifdef MODE
#define DEB(X) cout<< #X <<": "<<X<<" ";
#define DEB2(X) cout<<X<<" ";
#define END cout<<endl;
#else
#define DEB(X) {}
#define DEB2(X) {}
#define END {}
#endif
typedef long long ll;
#define int ll
#define uset unordered_set
#define umap unordered_map
//typedef std::pair<int,int> P;
struct edge{int to,cost;};
const int INF=100000000000000000;
const int INF2=9223372036854775807;
const int MOD=1000000007;
#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define min(X,Y) (((int)(X)<(int)(Y))?(X):(Y))
#define max(X,Y) (((int)(X)>(int)(Y))?(X):(Y))
#define NP(X,Y) next_permutation(X,Y)
#define setdouble(X,Y) cout<<fixed<<setprecision(X)<<Y
int ceil2(int a,int b){if(a%b==0){return a/b;}else{return a/b+1;}}
int pow2(int a,int b){int r=1;for(int i=1;i<=b;i++){r*=a;}return r;}
int Log2(int a){int t=0;while(1){if(a==0||a==1){break;}a/=2;t++;}return t;}

int A,B;

signed main(){
	cin>>A>>B;
	if(A>B){
		if(A<B+3){
			cout<<"Yes"<<endl;
		}
		else{
			cout<<"No"<<endl;
		}
	}
	else{
		if(A+3>B){
			cout<<"Yes"<<endl;
		}
		else{
			cout<<"No"<<endl;
		}
	}
	return 0;
}
