#include <iostream>
#include <algorithm>
#include <cctype>
using namespace std;

int main() {
    string s, t="";
    getline(cin, s);
    
    if(s.length()>100 || s.find('.')!=string::npos || s[0]=='.'){
        cout<<"Invalidn input";
        return 0;
    }
    for(char c:s)
       if(isalnum(c)) t+=tolower(c);
       
    string r=t;
    reverse(r.begin(), r.end());
    
    cout<<(t.empty() ? "Invalid input" : (t==r ? "Yes" : "No"));
    return o;
}