i need help starting this in c++. thank you !

In this assignment, you will create a very particular calculator that works with 3 integer numbers at a time rather than the usual 2 in regular calculators. The calculator is also particular in that the desired operation is provided ahead of the numbers: 1. So, first, ask the user to enter the desired operation (use cin) and store the value in a variable namechpperation. The user input will consist of a single letter or symbol. Entering: a) 'a' or 'A' gives the average (shown as a fractional number) b) 'M' gives the largest number c) 'c' or 'C' gives the middle number d) 'o' or 'O' gives the count of how many of the three numbers are even e) 'p' or 'P' tests whether any of the 3 numbers is divisible by 2,3 and 5 1) 'e' or 'E' tests whether all of the 3 numbers are different