largest = None
smallest = None

while True:
inp = raw_input("Enter a number: ")

if inp == 'done': break
if len(inp) < 1: break

try:
    num = int(inp)
except:
    print "Invalid input"
    continue

if smallest is None:
    smallest = num
elif inp < smallest:
    smallest = num

if largest is None:
    largest = num
elif inp > largest:
    largest = num

print "Maximum is %r" % (largest)
print "Minimum is %r" % (smallest)