largest = None
smallest = None
while True:
inp = input("Enter a number: ")
if inp == '0': break
try:
num = int(inp)
except:
print ("Invalid input")
continue
print (num)
if smallest is None: smallest = num
elif num < smallest: smallest = num
if largest is None: largest = num
elif num > largest: largest = num
print ("Maximum is %r" % (largest))
print ("Minimum is %r" % (smallest))