using System;
using System.Collections.Generic;

namespace MyCompiler {
    class Program {
        public static void Main(string[] args) {
            var map = new Dictionary<int, int>();
            
            // add entry to dictionary; throws an error if key already exists
            map.Add(1, 100);
            Console.WriteLine(map[1]);
            
            // update an entry in dictionary; add entry if key does not exist
            map[1] = 200;
            Console.WriteLine(map[1]);

        }
    }
}