#include<iostream> using namespace std; int main(){ char s[1000]; int i,n=0,flag=1; cin>>s; while(s[n]!='\0') n++; for(i=0;i<=n/2;i++){ if(s[i]!=s[n-1-i]){ flag=0; break; } } if(flag) cout<<"yes"<<endl; else cout<<"no"<<endl; }