#include <bits/stdc++.h>

using namespace std;
typedef long long ll ;
#define rep(i,a,n) for(int i=a ; i<n ; i++)
#define pb push_back

int main()
{
	int T=1;
	// cin >> T ;

	while(T--)
	{
		int x,y ;
		cin>>x>>y ;
		if(abs(x-y)<=2) cout<<"Yes\n" ;
		else cout<<"No\n" ;
	}
	return 0;
}
#include <bits/stdc++.h>

#define rep(i,n) for(int i=0; i<(n); ++i)
#define fixed_setprecision(n) fixed << setprecision((n))
#define execution_time(ti) printf("Execution Time: %.4lf sec\n", 1.0 * (clock() - ti) / CLOCKS_PER_SEC);
#define pai 3.1415926535897932384
#define NUM_MAX 2e18
#define NUM_MIN -1e9

using namespace std;
using ll = long long;
using P = pair<int,int>;
template<class T> inline bool chmax(T& a, T b){ if(a<b){ a=b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b){ if(a>b){ a=b; return 1; } return 0; }
const long long INF = 1LL << 60;

int main() {
    int x, y;
    cin >> x >> y;

    if(max(x, y) < min(x, y) + 3) cout << "Yes" << endl;
    else cout << "No" << endl;

    return 0;
}