For one, on line 30, you check if num2 > num3, but then you print num2 before num3.
On line 20 you see if num1 < num3, but you print out num1 last.
If you're only hardcoding 3 elements, you could do this a lot simpler with nested if-statements.
You could also change the separate if-statements to a chain of if, else if, else if, else statements, and at the end, if your code ever goes inside your "else" statement, you know which numbers caused an error.