#include<cstring>
using namespace std;
string s;
int main(){
	cin>>s;
	int len=s.size();
	int len1=len;
	for(int i=0; i<len/2; i++)
	{
		if(s[i]!=s[len1-1])
		{
			cout<<"no";
			return 0;
		}
		len1--;
	 }
	 cout<<"yes";
	 return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
	string s;
	getline ( cin, s );
	int len =s.size();
	int i = 0,j = len -1;
	while(j>i)
	{
		if ( s[j]!=s[i] )
		{
			cout<<"no"<<endl;
			return 0;
		 } 
		 i++;
		 j--;
	}
	
	
	
	
	cout<<"yes"<<endl;
	
	
	return 0;
 }

using namespace std;
int main()
{
	string s;
	getline ( cin, s );
	int len =s.size();
	int i = 0,j = len -1;
	while(j>i)
	{
		if ( s[j]!=s[i] )
		{
			cout<<"no"<<endl;
			return 0;
		 } 
		 i++;
		 j--;
	}
	
	
	
	
	cout<<"yes"<<endl;
	
	
	return 0;
 }

#include<bits/stdc++.h> using namespace std; string s; int main(){ string a,b; cin>>s; for(int i=0;i<s.size();i++){ a+=s[i]; } for(int i=s.size()-1;i>=0;i--){ b+=s[i]; } if(a==b){ cout<<"yes"; } else cout<<"no"; return 0; }