import java.util.Scanner;

public class Main {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    //思路：双指针或者库方法
    String s=sc.next();
    StringBuilder s2=new StringBuilder(s).reverse();
    if(s.equals(s2.toString()))System.out.println("yes");
    else System.out.println("no");
}   

}

#include <iostream #include <string using namespace std;

int main() { string s; getline(cin, s); // 读取整行，包含空格

int left = 0;
int right = s.length() - 1;
bool isPal = true;

while (left < right) {
    if (s[left] != s[right]) {
        isPal = false;
        break;
    }
    left++;
    right--;
}

cout << (isPal ? "yes" : "no") << endl;
return 0;

}

import sys
input=lambda:sys.stdin.readline().strip()

s=input()
i,j=0,len(s)-1
while(i<=j):
    if s[i] != s[j]:
        print("no")
        exit(0)
    i+=1
    j-=1
print("yes")