#include <iostream>
#include <string>
using namespace std;
int main() {
string s;
cin>>s;
bool x=true;
for( int i=0; i < s.length(); i++)
{if (s[i]!=s[s.length()-i]){x=false;}}
if(x){
cout<<"yes";
}
else {cout<<"no";}
return 0;
}
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