#include <bits/stdc++.h>

using namespace std;

#define  int           long long
#define  ld            long double
#define  pii           pair<int,int>
#define  pf            push_front
#define  pb            push_back
#define  ub            upper_bound
#define  lb            lower_bound
#define  ppb           pop_back
#define  ppf           pop_front
#define  f(i,a,b)      for(int i = a; i <  b; ++i)
#define  R(i,a,b)      for(int i = a; i >= b; --i)
#define  rep(i,a,b)    for(int i = a; i <= b; ++i)
#define  fr            first
#define  sc            second
#define  sz(x)         (int)((x).size())
#define  all(x)        (x).begin(),(x).end()

string s;

signed main()
{
    ios_base::sync_with_stdio(false);cin.tie(NULL);
    cin >> s;
    int n = s.length();
    int flag = 1;
    f(i,0,n){
        if((i&1)){
            if(islower(s[i])){
                flag = 0;
                break;
            }
        }else{
            if(isupper(s[i])){
                flag = 0;
                break;
            }
        }
    }
    if(flag) cout  << "Yes\n";
    else cout << "No\n";
    return 0;
}
#include <bits/stdc++.h>
using namespace std;

int main(){
  int cnt=0;
  string S;
  cin >>S;
  const char* cS=S.c_str();
  for(int i=0; i<S.size(); i++){
    if(i%2==0){
      if(cS[i]>=97){
        cnt++;
      }
    }
    else if(i%2==1){
      if(cS[i]<97){
        cnt++;
      }
    }
  }
  if(cnt==S.size()){
    cout << "Yes" <<endl;
  }
  else cout <<"No"<<endl;
}