#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int gcd(int a, int b) {  
  return b != 0 ? gcd(b, a % b) : a;
}//MAX
int lcm(int a, int b) { 
   return a * b / gcd(a, b);
   }
//MIN

 main() {
   string s;
   cin >> s;
   bool ans = true;
   for(int i=0;i<s.size();i++){
     if(s.size()%2==0&&s.at(i)!=' ')ans = false;
      if(s.size()%2==1&&s.at(i)==' ')ans =false;
   }
   if(ans) cout<<"Yes"<<endl;
   else{
     cout<<"No"<<endl;
   }
}