Python quest urgent : Write a program that uses a while loop
Process input that uses a sentinel value to indicate the end of input

Write a program that reads a series of numbers from standard input and prints out the sum of those values.  A sentinel value of -999 will indicate the end of the input values.  Do not include the sentinel value in the sum.

Can anyone help me with this?
This is what i have tried
`user_input = 1
    while user_input = -999:
        user_input = int(input())`
