#include<bits/stdc++.h>
using namespace std;
int main(){
int a,b;
cin>>a>>b;
if(a%2==0&&b%2==0||a%2==1&&b%2==1)
{
cout<<"yes";
}
else
{
cout<<"no";
}
return 0;
}
#include<bits/stdc++.h>
using namespace std;
int main(){
int a,b;
cin>>a>>b;
if(a%2==0&&b%2==0||a%2==1&&b%2==1)
{
cout<<"yes";
}
else
{
cout<<"no";
}
return 0;
}