Which two numbers should be interchanged to make the given equation correct?

(99 − 42 + 11) + (36 ÷ 6) × 7 − 50 = 73

(NOTE: Numbers must be interchanged and not the constituent digits e.g. if 2 and 3 are to be interchanged in the equation 43 × 3 + 4 ÷ 2, then interchanged equation is 43 × 2 + 4 ÷ 3)