write a program that prints the day number of the year given the date in the form month-day-year
ex.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 leap if its divisible by 4 but not divisible by 100
ex.1992 & 2008
a year is divisible by 100 is a leap year if its also divisible by 400
ex.1600 & 2000
1800 is not a leap year because its not divisible by 400