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

#define ?N?110

char ?str[ 10 ];
char ?queue[N][ 100 ];
int ??top = ? 0 ;
int ??len = ? 1 ;

int ?main()
{
????strcpy(?queue[ ++ top],? " http://www.acm.org/ " ?);
????
???? while (?scanf( " %s " ,?str),?strcmp(?str,? " QUIT " ) != ? 0 ?)
???? {
???????? if (?strcmp(?str,? " VISIT " ) == ? 0 ?)
???????? {
????????????scanf( " %s " ,?queue[ ++ top]?);
????????????printf( " %s\n " ,?queue[top]?);
????????????
????????????len = ?top;
????????}
???????? else ? if (?strcmp(?str,? " BACK " ?) == ? 0 ?)
???????? {
????????????top -- ;
???????????? if (?top < ? 1 ?)
???????????? {
????????????????printf( " Ignored\n " );
????????????????top ++ ;
????????????}
???????????? else ?printf( " %s\n " ,?queue[top]?);
????????}
???????? else ? if (?strcmp(?str,? " FORWARD " ?) == ? 0 ?)
???????? {
????????????top ++ ;
????????????
???????????? if (?top > ?len?)? {??printf( " Ignored\n " );??top -- ;?}
???????????? else ??printf( " %s\n " ,?queue[top]?);
????????}
????}
????
???? return ? 0 ;
}