A system has one output, F, and four inputs (A, B, C, D), where the first two inputs (A, B) represent one 2-bit unsigned binary number and the second two inputs (C, D) represent another unsigned binary number. F is to be 1 if and only if the sum of the two numbers (A, B + C, D) is odd. Show a truth table for the system, and use a K-map to find the minimum sum-of-products expression for F.