  How many Sundays fell on the first of the month during the twentieth century (1 Jan 1901 to 31 Dec 2000)?
  */
 func isLeapYear(year:Int) -> Bool {
-    let isLeap:Bool = (year % 4 == 0) && (year % 400 != 0)
+    let isLeap:Bool = (year % 4 == 0) && ((year % 400 == 0) || (year % 100 != 0))
     return isLeap
 }
 

                month += 1
            }
            weekDay = (weekDay + 1) % 7
            print("\(year, month,day)=\(weekDay)")

            // special
            if (weekDay == 0 && day == 1) {
                specialSunndays += 1
            }
        }
        

/*
 Counting Sundays
 Problem 19
 171
 
 You are given the following information, but you may prefer to do some research for yourself.
 
