To my knowledge the only fully working HolyC compiler exists in TempleOS.
The .ISO
can be downloaded from the official website TempleOS which can be installed in your favorite virtual machine.
To execute the program type this into the TempleOS console.
#include "HCCalculator.HC"
After executing the calculator you can enter the first number.
Enter first number: 5 # 5 is the input
Then choose between the calculation functions.
Choose between:
1) Addition
2) Subtraction
3) Multiplication
4) Division
1 # < This is our input
We now can enter the second number
Enter second number: 2 # 2 is the input
Now it should give the right output.
7 # 7 is the return value