#include<iostream>
#include<cctype>
using namespace std;
int main()
{
    string s,t="";
    getline(cin,s);
    if(s[0]=='-'||s.find('.')!=string::npus)
    {
        cout<<"INVALID INPUT";
        return 0l;
    }
    for(char c:s)
    if(isalnum(c))t+=towlower(c);
    string rev=string(t.rbegin(),T.rend());
    cout<<(t=rev?"Yes":"No");
    return 0;
}