#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vd = vector<double>;
using vp = vector<P>;
using vs = vector<string>;
using vb = vector<bool>;
using pq = priority_queue<int,vector<int>,greater<int>>;/*top()で最小値取得*/
using pq2 = priority_queue<int, vector<int>, less<int>>;/*top()で最大値取得*/

#define INF 1000000005
#define mod 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i = 0; i < (n); ++i) /*0からn-1までのrep*/
#define rrep(i,n) for(int i = 1; i <= (n); ++i) /*1からnまでのrep*/
#define drep(i,n) for(int i = (n)-1; i >= 0; --i) /*n-1から0までのrep*/
#define srep(i,s,t) for (int i = s; i < t; ++i) /*sからt-1までのrep*/
#define each(a,b) for(auto& (a): (b)) /*よくわからん*/
#define all(v) (v).begin(),(v).end() /*全選択*/
#define sz(v) (int)(v).size() /*大きさ*/
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end()) /*重複削除*/
#define cmx(x,y) x=max(x,y) /*最大値*/
#define cmn(x,y) x=min(x,y) /*最小値*/
#define fi first
#define se second
#define pb push_back //a.push_back(最後に任意の数字を追加); a.pop_back();
#define rev(v) reverse((v).begin(),(v).end());
#define sob(v) sort((v).begin(), (v).end(),greater<int>()); /*大きい順にソート*/
#define so(v) sort((v).begin(), (v).end()); /*小さい順にソート*/
#define yn {puts("Yes");}else{puts("No");}
#define dame { puts("-1"); return 0;}/*だめ*/
const double eps = 1e-10;
const ll MOD = 1000000007;
constexpr ll MAX = 5000000;

ll gcd(ll a, ll b) { return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) { return a/gcd(a,b)*b;}

int ctoi(char c) {
	switch (c) {
		case '0': return 0;
		case '1': return 1;
		case '2': return 2;
		case '3': return 3;
		case '4': return 4;
		case '5': return 5;
		case '6': return 6;
		case '7': return 7;
		case '8': return 8;
		case '9': return 9;
		default: return 0;
	}
}

ll divup(ll x, ll y){
	if(x%y==0){
		return x/y;
	} else {
		return x/y + 1;
	}
}

int main(){
	int x,y;
	cin >> x >> y;
	if(abs(x-y)>=3){
		cout<<"No"<<endl;
	} else {
		cout<<"Yes"<<endl;
	}
	return 0;
}
#include<bits/stdc++.h>
#define maxn 1000005
#define inf 9999999999999999
#define mod 1000000007
typedef long long LL;
using namespace std;
int main()
{
    ios::sync_with_stdio(false);
    //freopen("bwxnQAQin.txt","r",stdin);
    LL x,y;
    cin>>x>>y;
    if(abs(x-y)<3)cout<<"Yes";
    else cout<<"No";
    return 0;
}
