#include <bits/stdc++.h> using namespace std; int main(){ char a[1001]={}; int n=0,d=0; cin>>a; while(a[n]!='/0'){ n++; } for(int i=0;i<n;i++){ if(a[i]!=a[n-1-i]){ cout<<"no"<<endl; d++; break; } } if(d!=1){ cout<<"yes"<<endl; } return 0; }