package lanqiaobei;
import java.util.*;
public class Main {
static Scanner in =new Scanner(System.in);
static final int N=1000;
static int k;
public static void main(String[] args) {
while(in.hasNext()){
String s=in.next();
Stack<Character> st=new Stack<Character>();
st.clear();
int l=s.length();
int mid=0;
if(l%2==0)
mid=l/2;
else
mid=l/2+1;
for (int i = 0; i <l/2; i++){
st.push(s.charAt(i));
}
for (int i = mid; i < l; i++) {
if(s.charAt(i)!=st.peek())
break;
st.pop();
}
if(st.isEmpty())
System.out.println("Yes");
else
System.out.println("No");
}
}
}利用栈来判断回文简单，注意奇偶的处理即可
