Declare a character variable letterStart. Write a statement to read a letter from the user into letterStart, followed by statements that output that letter and the next letter in the alphabet. End with a newline. Note: A letter is stored as its ASCII number, so adding 1 yields the next letter. Sample output assuming the user enters 'd': De Hint -- Replace the ?s in the following code: char letterStart; cin >> ?; cout << letterStart; letterStart = ?; cout << letterStart << endl;