Structures, display message?

[SMA01]

I need to write a program where a user can either enter 2 distances and the program will add these distances, or user can enter 1 distance and 1 time and then the program will calculate the rate. This is done using a structure composed of three fields (all integers): feet, yards, miles. My question is, what should my display message say? Should it ask the user to enter two values? Because there are two options that a user can choose from.

Thanks.

[Darkmaster]

let the user select and read his input with std::cin