Solution.cs

using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.Serialization;
using System.Text.RegularExpressions;
using System.Text;
using System;

class Solution {
    const int BIRD_TYPE_COUNT = 5;
    // Complete the migratoryBirds function below.
    static int migratoryBirds(List<int> arr) {
        var counter = new int[BIRD_TYPE_COUNT];
        foreach(var bird in arr)
            counter[bird-1]++;
        
        var max = counter.First();
        var resultType = 1;
        for(int i = 1; i<BIRD_TYPE_COUNT; i++) {
            if(counter[i] > max) {
                max = counter[i];
                resultType = i+1;
            }
        }
        return resultType;
    }

    static void Main(string[] args) {
        TextWriter textWriter = new StreamWriter(@System.Environment.GetEnvironmentVariable("OUTPUT_PATH"), true);

        int arrCount = Convert.ToInt32(Console.ReadLine().Trim());

        List<int> arr = Console.ReadLine().TrimEnd().Split(' ').ToList().Select(arrTemp => Convert.ToInt32(arrTemp)).ToList();

        int result = migratoryBirds(arr);

        textWriter.WriteLine(result);

        textWriter.Flush();
        textWriter.Close();
    }
}