sentinel = raw_input("What shall the sentinel be? ")

entered = sentinel + " "
array = []

while entered != sentinel:
    entered = raw_input("Enter a number to be added to the array: ")
    if entered != sentinel: array.append(int(entered))

array.sort()
lowest = array[0]
highest = array[len(array) - 1]
print "The lowest number is " + str(lowest) + ", while the highest is " + str(highest) + "."