# a function which returns the maximum of its two parameters

def max2(a,b):
    '''
    max(float,float)  ---> float
    return the maximum od a and b
    '''
    if a>=b:
        return a
    else:
        return b

# a function which returns the maximum of its three parameters

# version 1
def max3_v1(a,b,c):
    if a>=b:
        if a>=c:
            return a
        else:
            return c
    else:
        if b>=c:
            return b
        else:
            return c

# version 2
def max3_v2(a,b,c):
    return max2(max2(a,b), c)

# version 3
def max3_v3(a,b,c):
    if a>=b and a>=c:
        return a
    elif b>=a and b>=c:
        return b
    else:
        return c

# what is the maximal number of comparison performed by each of the versions
# for the worst-case input ?