/* -*- coding: utf-8 -*-
 *
 * 908.cc:  No.908 うしたぷにきあくん文字列 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 128;

/* typedef */

/* global variables */

char s[MAX_N];

/* subroutines */

/* main */

int main() {
  fgets(s, MAX_N, stdin);

  for (int i = 0; s[i] >= ' '; i++)
    if ((! (i & 1) && s[i] == ' ') ||
	((i & 1) && s[i] != ' ')) {
      puts("No");
      return 0;
    }

  puts("Yes");
  return 0;
}