#include<bits/stdc++.h>
using namespace std;
#define F                 first
#define S                 second
#define int               long long
#define pb                push_back
#define mp                make_pair
#define pii               pair<int,int>
#define vec               vector<int>
#define mii               map<int,int>
#define pqb               priority_queue<int>
#define no_of_test(zzz)   int zzz; cin>>zzz; while(zzz--)
#define p(c)              cout<<c<<'\n';
#define f(i,a,b)          for(int i=a;i<b;i++)
const int mod = 1e9 + 7;
int32_t main()
{
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	//no_of_test(zzz)
	{
		int x,y;
        cin>>x>>y;
        int k=abs(x-y);
        if(k<3)
        cout<<"Yes"<<'\n';
        else
        {
            cout<<"No"<<'\n';
        }
        

	}
	return 0;
}
//cout<<"###"<<'\n';
//cout<<"."<<'\n';
//cout<<"****"<<'\n';
/*
NO
YES
NO
YES
NO
YES
*/



#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize(2)
typedef long long ll;
const int N=1e6+5;
const int inf=0x3f3f3f3f;
ll gcd(ll a,ll b)//最大公约数 
{
    return b==0?a:gcd(b,a%b);
}
ll lcm(ll a,ll b)//最小公倍数 
{
	return a*b/gcd(a,b);
}
ll quick_pow(ll x, ll n)//快速幂 
{
    ll num=x,ansult=1;
    while(n)
	{
        if(n%2)
            ansult*=num;
        num*=num;
        n/=2;
    }
    return ansult;
}
ll extra_gcd(ll a,ll b,ll &x,ll &y)//扩展欧几里得(递归)-求逆元 
{
	if(!b)
	{
		x=1;
		y=0;
		return a;
	}
	ll exgcd=extra_gcd(b,a%b,y,x);
	y-=a/b*x;
	return exgcd;
}
int flag(int a)
{
	; 
}
ll read() 
{
	ll c=getchar(),Nig=1,x=0;
	while(!isdigit(c)&&c!='-')c=getchar();
	if(c=='-')Nig=-1,c=getchar();
	while(isdigit(c))x=((x<<1)+(x<<3))+(c^'0'),c=getchar();
	return Nig*x;
}
void out(int a)  
{
    if(a > 9)
    {
        out(a/10);
    }
    putchar(a%10 + '0');
}
ll num[105],n;
void visit()
{
	for(int i=1;i<=n;i++)
	{
		cout<<num[i]<<" ";
	}
	cout<<endl;
}
void Del(int x)
{
	for(ll i=x;i<n;i++)
	{
		num[i]=num[i+1];
	}
	n--;
			
}
int main()
{
	ll x,y;
	x=read();
	y=read();
	if(abs(x-y)<3)
	{
		printf("Yes\n");
	}
	else
	{
		printf("No\n");
	}
	return 0;
}