Identify the major flaws in the following code snippet.
Input: def add_numbers(x,y):
    return x+y

add_numbers(2)
1. The function add_numbers() has two inputs, but only expects one.
2. The return value of the function add_numbers() is not used.
The major flaws in the code snippet are that it does not check if x or y is negative, and the return statement is missing a semicolon after the 'return' keyword. The code should instead look like this: 

def add_numbers(x,y):
    if x < 0 and y < 0:
        pass
    elif x > 0 and y > 0:
        return x + y
    else:
        pass
    return x + y;