Many programs that require moving character data from one place to another use a checksum mechanism to ensure that the data are transferred correctly. The checksum technique requires a function that sums the code values of all the characters being sent. If the letters a, b, and c are being sent, for instance, the sum would be 294 because the ASCII values of these characters are 97, 98, and 99. The sending part of the program would then send this sum value along with the characters. The receiving part of the program computes the sum of the characters it receives and compares it with the sum from the sending component. If the sums match, there is a high probability that the data were transferred correctly. Write a checksum () function that returns the sum of a line entered from the keyboard. Use an unsigned integer to store the sum so that the value will behave predictably if an overflow occurs.