# Program to calculate the average of 3 numbers
# using a function call.

def avg(n1, n2, n3):
    return (n1 + n2 + n3)/3.0

# Main program begins here.

print("Enter 3 numbers")
n1 = float( input() )
n2 = float( input() )
n3 = float( input() )

result = avg( n1, n2, n3)
print("The mean value is : ", result)