#include<bits/stdc++.h>
#define lint long long int
#define rep(i,n) for(int i=0;i<int(n);i++)
#define arep(i,a,n) for(int i=a;i<n;i++)
#define sort(a) sort(a.begin(),a.end())
#define reverse(a) reverse(a.begin(),a.end())
#define fill(a,x) fill(a.begin(),a.end(),x)
#define pb push_back
#define mp make_pair
#define AlphabetNUM 26
#define vint vector<int>
using namespace std;

template<typename T>istream& operator >> (istream& is, vector<T>& vec){for(T& x: vec) is >> x;return is;}
template<typename T>T gcd( T a,T b){if(b==0)return a;return gcd(b,a%b);}
template<typename T>bool chmax(T& a,T b){if(a<b){a=b;return true;}else{return false;}}
template<typename T>bool chmin(T& a,T b){if(a>b){a=b;return false;}else{return true;}}
template<typename T>T lcm(T a, T b){return a * b / gcd(a, b);}
template<typename T>void out(T data){cout<<data<<endl;}
lint MOD=pow(10,9)+7;
int inf=-1+pow(2,31);
int dirx[]={0,1,0,-1};
int diry[]={-1,0,1,0};


int main(){
	string s;
	cin>>s;
	int n=s.size();
	rep(i,n){
		if(i%2==0){
			if(s[i]==' '){
				out("No");
				return 0;
			}
		}else{
			if(s[i]!=' '){
				out("No");
				return 0;
			}
		}
	}
	out("Yes");
	return 0;
}