# include<iostream> # include<string> # include<cstring> using namespace std; int main(){ string a; int n,b=0; cin>>a; n=a.size(); for(int i=0;i<=n/2;i++){ if(a[i]!=a[n-i-1]) b=1; } if(b==1) cout<<"NO"; else cout<<"YES"; return 0; }