# -*- coding: iso-8859-1 -*-
# calcutron.py

while True:
    print "(a)dd, (s)ubtract, (m)ultiply, (d)ivide, (q)uit"
    operation = raw_input('Give an operation: ')

    if operation == 'a' or operation == 's' or operation == 'm' or operation == 'd':

        first = float(input('First number: '))
        second = float(input('Second number: '))
        if operation == 'a':
            result = first + second
            print '%.1f' %(result)

        elif operation == 's':
            result = first - second
            print '%.1f' %(result)

        elif operation == 'm':
            result = first * second
            print '%.1f' %(result)

        elif operation == 'd':
            if second == 0:
                print "Cannot divide by zero."
            else:
                result = first / second
                print '%.1f' %(result)

    elif operation == 'q':
            break

    else:
        print "WHAT ARE YOU DOING?"