#include <iostream>
#include <cmath>

int main() {
    int x, y;
    std::cin >> x;
    std::cin >> y;
    std::cout << (std::abs(x-y) < 3 ? "Yes" : "No") << std::endl;
    return 0;
}
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vl = vector<ll>;
using vp = vector<pii>;
using vvi = vector<vi>;
#define rep(i, a, b) for (int i = a; i < (int) (b); i++)
#define rrep(i, a, b) for (int i = a; i >= (int) (b); i--)
#define fore(i_in, a) for (auto& i_in: a)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pq(T) priority_queue<T, vector<T>, greater<T>>
template<class T> void chmin(T &a, T b) { if (a > b) a = b; }
//template<class T> bool chmin(T& a, T b) {if (a > b) {a = b;return true;} else return false;}
template<class T> void chmax(T &a, T b) { if (a < b) a = b; }
//template<class T> bool chmax(T& a, T b) {if (a < b) {a = b;return true;} else return false;}
template<class T> void print(const T &t) { cout << t << "\n"; }

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int h, w; cin>>h>>w;
    if (abs(h-w) < 3) print("Yes");
    else print("No");
}
