#include <bits/stdc++.h>
using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    string s;
	getline(cin ,s);
	int evencount = 0;
	int oddcount = 0;
	int len = s.length();
	for(int i = 0 ; i < len; i += 2) {
		if(islower(s[i])) {
			evencount++;
		}
	}
	for(int i = 1; i < len; i += 2) {
		if(s[i] == ' ') {
			oddcount++;
		}
	}
	if(oddcount + evencount == len) {
		cout << "Yes" << endl;
	}else {
		cout << "No" << endl;
	}
}