#!/usr/bin/env ruby -w
#
# Leap years
# "Learn to Program" by Chris Pine, p. 56

print 'Starting year: '
start_year = gets.to_i
print 'Ending year: '
end_year = gets.to_i

year = start_year
while year <= end_year
    leap = false
    if year % 4 == 0
        puts "#{year} is a leap year" unless
            year % 100 == 0 and year % 400 != 0
    end
    year = year + 1
end