Write a loop that displays all possible combinations of two letters where the letters are 'a', or 'b', or 'c', or 'd', or 'e'. The combinations should be displayed in ascending alphabetical order:
aa
ab
ac
ad
ae
ba

Some of the first computer games were created in the early 1970s by college students experimenting after hours to see what the were capable of doing.

Font size, font style, and are all aspects of character formatting.

Write a program that prints the day number of the year, given the date in the form month-day-year. for example, if the input is 1-1-2006, the day number is 1; if the input is 12-25-2006, the day number is 359. the program should check for a leap year. a year is a leap year if it is divisible by 4, but not divisible by 100. for example, 1992 and 2008 are divisible by 4, but not by 100. a year that is divisible by 100 is a leap year if it is also divisible by 400. for example, 1600 and 2000 are divisible by 400. however, 1800 is not a leap year because 1800 is not divisible by 400.