Weight/height only take integer values, and crashes if non-ints are supplied

[Artemis-Hunt]

When entering info during initialization, if age/height/weight etc. given is not a valid integer e.g. %% or 21.1 or even a number beyond MAX_INT/MIN_INT (2147483647/-2147483648) it will cause the program to crash with NumberFormatException.

This is an issue when users want to enter a height of 178.5 or weight of 60.2 which is perfectly valid, yet causes program to crash