#include<iostream>
#include<string>
#include<alogrithm>
int main() {
    string word1,word2;
    cin>>word1;
    word2=word1;
    reverse(word1begin(),word1.end());
    if(word1=word2)
    {
        cout<<"YES";
    }
    else{
        cout<<"NO";
    }
}