import sys

#
# Get numbers a and b from the user (allow user to repeat until succes)
#
success = False
while success == False:
  success = True
  try:
    a = input("Enter a: ")
    b = input("Enter b: ")

  except NameError:
    success = False
    print "That wasn't a number -- try again"

  except:
    print "Something bad happened!"
    sys.exit()


#
# compute a+b, a-b, a*b, a/b, catching divide by zero exception if generated
# as opposed to crashing!
#
print a,"*",b,"=",a*b
print a,"+",b,"=",a+b
print a,"-",b,"=",a-b

try:
  print a,"/",b,"=",a/float(b)

except ZeroDivisionError:
  print "Division by zero is not supported!"

print "Program complete"