#include <iostream>
#include <stdio.h>
#include <string.h>
#include <math.h>
#define maxn 300
using namespace std;
char str[maxn];
bool isBackStr() {
bool flag = true;
int half, len = strlen(str);
if(len % 2) half = (len - 1) / 2;
else half = len / 2;
for(int i = 0; i < half; i++) {
if(str[i] != str[len-1-i]) {
flag = false;
break;
}
}
return flag;
}
int main() {
// FILE* in = fopen("/home/zzz/input.txt", "r");
// while (fscanf(in, "%s", str) != EOF) {
// if(isBackStr()) cout << "YES" << endl;
// else cout << "NO" << endl;
// }
while (scanf( "%s", str) != EOF) {
if(isBackStr()) cout << "YES" << endl;
else cout << "NO" << endl;
}
return 0;
}