# include <stdio.h>
# include <string.h>
typedef char Str50[50] ;
int main() {
Str50 str1 ;
int i = 0, j = 0 ;
while ( scanf( "%s", str1 ) != EOF ) {
int length = strlen(str1) ;
for ( int i = 0, j = length - 1 ; i < length, j >= 0 ; i++, j-- ) {
if ( str1[i] != str1[j] )
printf( "no\n" ) ;
} // for
if ( str1[i] == str1[j] )
printf( "yes\n") ;
} // while
} // main()