using System;

namespace MyCompiler {
    class Program {
        public static void Main(string[] args) {
            int[] nums = {1,2,3};
            
            // use string.Join(separator, array)
            Console.WriteLine("[" + string.Join(", ", nums) + "]");
            Console.WriteLine($"[{string.Join(", ", nums)}]");
            Console.WriteLine("[{0}]", string.Join(", ", nums));
        }
    }
}