    #include <bits/stdc++.h>
    using namespace std;
     
    int main(){
      int x,y;
      cin >> x >> y;

      if(abs(x-y) >= 3){
         cout << "No" << endl;
      }
      else{
         cout << "Yes" << endl;
      }
    }
#include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
#define rep(i,n) for(int i=0;i<(n);++i)
#define repi(i,a,b) for(int i=int(a);i<int(b);++i)
#define rrep(i,n) for(int i=((n)-1);i>=0;--i)
#define all(x) (x).begin(), (x).end()
#define PI 3.14159265358979323846264338327950L
#define mod 1000000007
using namespace std;
typedef long long ll;
typedef long double ld;
int main() {
    int x,y;
    cin>>x>>y;
    if(x<y&&x+3>y) cout<<"Yes";
    else if(y<x&&y+3>x) cout<<"Yes";
    else cout<<"No";
}