Now, we can solve for k and m. We know that k and m are positive integers, so the only possible values for k are 1, 2, or 3. If k = 1, then 4242 = 1401 + 2m. This means that m = 2841, which is not less than 50. If k = 2, then 4242 = 2802 + 2m. This means that m = 1440, which is not less than 50. If k = 3, then 4242 = 4203 + 2m. This means that m = 7, which is less than 50. Therefore, k = 3 and m = 7. The value of k + m is 3 + 7 = 10. Answer: The value of k + m is 10.