using System;

namespace TestsDecimals
{
    public static class Program
    {
        public static void Main(string[] args)
        {
            var a = new A();
            a.SetA(5);
            a.SetB(6);
            Console.WriteLine(a.GetA);    // 5
            Console.WriteLine(a.GetB);    // 6
            Console.WriteLine(a.C);        // 5 * 6 = 30
        }
    }

    public class A
    {
        private int _a;
        private int _b;

        // setters
        public void SetA(int a) => _a = a;
        public void SetB(int b) => _b = b;

        // getters
        public int GetA => _a;
        public int GetB => _b;

        public int C => _a * _b;
    }
}