Palidrom 4x

#include <iostream>
using namespace std;
int main() {
  int a, b, c, d;
  cin >> a;
  d = a % 10;
  c = a / 10 % 10;
  b = a / 100 % 10;
  a = a / 1000;
  if (a == d && b == c) {
    cout << "YES";
  } else {
    cout << "NO";
  }
  return 0;
}