#include<bits/stdc++.h> using namespace std; int main() { char s[100]; int len,position; int i,j; gets(s); len=strlen(s); i=0; j=len-1; while(i<j&&s[i]==s[j]) { i++; j--; } if(i>=j) cout<<"yes"<<'\n'; else cout<<"no"<<'\n'; return 0; }