Charles is in charge of running a single elimination tournament. In such a tournament, teams play until they lose a game. Charles had a stack of paper, each sheet containing the results of a game in this tournament. During the tournament, after every team had played at least one game, he was walking down the hallway, when he tripped and chucked the stack of results all over the place. Since the papers were completely scattered, he needs your help figuring out which teams are still in the tournament. Input Format The input to the program is a list of game results in the following format: Team1 Score1 Team2 Score2 Where Team1 is the away team's name Score1 is the away team's score Team2 is the home team's name Score2 is the home team's score Constraints The scores will be integers greater than 0 and less than 200. The team names will be alphabetic strings containing no spaces. No games resulted in a tie. Output Format The output of the program is a list of the undefeated teams in alphabetical order, with one team per line. Sample Input 0 Chargers 87 Doves 70 Giants 3 Heat 1 Bucks 98 Lions 67 Avalanche 10 Bucks 20 Chargers 27 Oilers 14 Islanders 60 Jaguars 15 Kings 17 Lakers 27 Giants 3 Lakers 1 Islanders 15 Flyers 27 Panthers 2 Flyers 4 Lions 104 Magic 98 Nationals 8 Oilers 15 Sample Output 0 Bucks Chargers Flyers Giants