#include<iostream> #include<cstring> using namespace std; int main() { char a[105]; cin>>a; int n=strlen(a); int cnt=0; for(int i=0;i<n/2;i++){ if(a[i]!=a[n-i-1]) break; if(a[i]==a[n-i-1]) cnt++; } if(cnt==n/2) cout<<"yes"; else cout<<"no"; return 0; }