#include <bits/stdc++.h>   using namespace std;   template <typename T>   T gcd(T a, T b) {     return (b == 0) ? a : gcd(b, a % b);   }   template <typename T>   T lcm(T a, T b) {     return a * (b / gcd(a, b));   }   template <typename T>   T mod_exp(T b, T p, T m) {     T x = 1;     while (p) {       if (p & 1) x = (x * b) % m;       b = (b * b) % m;       p = p >> 1;     }     return x;   }   template <typename T>   T invFermat(T a, T p) {     return mod_exp(a, p - 2, p);   }   template <typename T>   T exp(T b, T p) {     T x = 1;     while (p) {       if (p & 1) x = (x * b);       b = (b * b);       p = p >> 1;     }     return x;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     ;     int a, b;     cin >> a >> b;     if (a == 0 && b == 0) {       cout <<  NO  <<   n ;     } else if (abs(a - b) <= 1)       cout <<  YES  <<   n ;     else       cout <<  NO  <<   n ;     return 0;   }   