Why wont my code work? Python

print(“This is a slope calculator.”)
x_value1 = int(input("give me your first x value: "))
x_value2 = int(input("give me your second x value: "))
add_x = x_value2 - x_value1
y_value1 = int(input("give me your first y value: "))
y_value2 = int(input("give me your second y value: "))
add_y = y_value2 - y_value2
slope = add_y / add_x
print(slope)
my code only prints either 0.00 or -0.00
can you help me?

Might be this part…