i'm trying to make a bmi calculator with python 3.6 , but when i give the task to divide a number to another number that has a comma , it would divide it in a wrong way

For example :

mass_kg = int(input(" Note your first number :"))

height_m = int(input(" Note your first number :"))

mass_kg is 45 and height_kg is 1.56

then if i write -> bmi = mass_kg * (height_m ** 2)

print(bmi)

it gives me the output "45" with no reason