#include<string>
#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
    string s1;
    getline(cin,s1);
    int left = 0 ;
    int right = s1.size()-1;
    while(left<right)
    {
        if(s1[left]!=s1[right])
        {
            cout<<"no";
            return 0;
        }
        left++;
        right--;
    }
    cout<<"yes";
    return 0;
}