public Theatre(String theatreName, int numRows, int seatsPerRow) {
this.theatreName = theatreName;

int lastRow = 'A' + (numRows -1);
for (char row = 'A'; row <= lastRow; row++) {
for(int seatNum = 1; seatNum <= seatsPerRow; seatNum++) {
Seat seat = new Seat(row + String.format(%02d, seatNum));
seats.add(seat);
}
}
}