# Matt Bishop, MHI 289I
##
## This is the program we wrote in class on January 22
## I added a few comments (they begin with "##")
##
## Given the lengths of the two legs of a right triangle,
## computew the length of the hypotenuse using the 
## Pythagorean theorem
##
## Load the math module so we can use the sqrt method
import math

##
## Indefinite loop; exit is at the end using a "break"
##
while True:
    # read in a, b
    try:
        a = float(raw_input("First side: "))
        b = float(raw_input("Second side: "))
    except:
        ## Something entered was not a float
        print "One of these is not a float!!!!!"
    else:
        ## check the lengths of the sides are non-negative
        if a < 0 or b < 0:
            print "Both numbers must be non-negative"
        else:
            # compute sqrt of a^2 and b^2
            c = math.sqrt(a**2 + b**2)
            # print it
            print c
    # ask user if she wants to continue
    contin = raw_input("Do you want to continue? (y or n): ")
    ## if anything other than "y" or "n", ask again
    while contin != "y" and contin != "n":
        print "y or n only, please!"
        contin = raw_input("Do you want to continue? (y or n): ")
    ## if user typed "n", quit
    if (contin == "n"):
        break