I am given 3 int, a, b, c. I would like to find the sum of all three int provided that they are unique. If a, b, or c has the same values as any of the other values, then they don't count towards the sum.

Example 1:

```
a = 3, b = 3, c =3
sum = 0

```

Example 2

```
a = 1, b = 3, c =3
sum = 1

```

This is what I have done. Is there a more pythonic way of doing this without so many if else statements?

```
def lone_sum(a, b, c):
    if a != b and b != c and a != c:
        return a + b + c

    elif a == b == c:
        return 0

    elif a == b:
        return c

    elif b == c:
        return a

    elif a == c:
        return b

```