C Program Execution of a loop an unknown number of times

/* Execution of a loop an unknown number of times */
main( )
{
char  another ;
int  num ;
do
{
printf ( "Enter a number " ) ;
scanf ( "%d", &num ) ;
printf ( "square of %d is %d", num, num * num ) ;
printf ( "\nWant to enter another number y/n " ) ;
scanf ( " %c", &another ) ;
} while ( another == 'y' ) ;
}