#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int
ispalin (char *s);

int
main (void)
{
	char s [100];

	while (gets (s) != NULL) {
		if (ispalin (s))
			printf ("yes\n");
		else
			printf ("no\n");
	}

	return 0;
}

int
ispalin (char *s)
{
	int i, j;
	char s1 [100];

	j = 0;

	for (i = strlen (s) - 1; i >= 0; i--) {
		s1 [j] = s [i];
		j++;
	}

	s1 [j] = '\0';

	if (!strcmp (s, s1))
		return 1;
	else
		return 0;
}