#include<stdio.h>
int huiwen(char* str)
{
int n = strlen(str);
char* left = str;
char* right = str + n - 1;
while (left < right)
{
if (*left != *right)
return 0;
left++;
right--;
}
return 1;
}
int main()
{
char arr[30];
scanf("%s", arr);
int n = huiwen(arr);
if (n == 0)
printf("no");
else
printf("yes");
return 0;
}