#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b;cin>>a>>b;
	if(a==1 and b==10 or a==10 and b==1) cout<<"Yes";
	else{
		if (abs(a-b)==1) cout<<"Yes";
		else cout<<"No";
	}
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int a,b;
int main(){
	cin>>a>>b;
	if(abs(a-b)==1){
		cout<<"Yes";
	}else if(a==1&&b==10||a==10&&b==1){
		cout<<"Yes";
	}else{
		cout<<"No";
	}
	
	
	return 0;
}