#include <bits/stdc++.h>
using namespace std;
    
#define fi first
#define se second
#define pb push_back
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define FOR(i, a, b) for (int i = a; i <= (b); i++)
#define ROF(i, a, b) for (int i = a; i >= (b); i--)
#define y1 awefakhlrv

using pii = pair<int, int>; using vpii = vector<pii>;
using vi = vector<int>; using vvi = vector<vi>;
using ll = long long;
using pll = pair<ll, ll>; using vpll = vector<pll>;
using vll = vector<ll>; using vvll = vector<vll>;

int main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int x, y; cin >> x >> y;
    cout <<  (abs(x - y) <= 2 ? "Yes" : "No") << endl;
}
#include <bits/stdc++.h>
using namespace std;

int main(){
    int x, y;
    cin >> x >> y;
    if((x < y && y - x < 3) || (x > y && x - y < 3)){
        cout << "Yes" << endl;
    }else{
        cout << "No" << endl;
    }
}