2일차 구구단 중에 원하는 단을 입력해주세요. FormatException 에러 해결

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using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;   namespace Syntax02 {     class Program     {         static void Main(string[] args)         {             int num = -1;             bool repeat = true;                              while (repeat)             {                 Console.Write("구구단중에 원하는 단을 입력해주세요. ");                 string input = Console.ReadLine();                 try                 {                     num = Convert.ToInt32(input);                     if (num < Int32.MaxValue)                     {                         for (int i = 1; i < 10; i++)                         {                             Console.WriteLine($"{num} x {i} = {num * i}");                         }                     }                     else                     {                         Console.WriteLine("num이 -2,147,483,648 and +2,147,483,647을 초과합니다.");                     }                 }                 catch (FormatException)                 {                     Console.WriteLine("입력된 문자열은 정수가 아닙니다.");                 }                 catch (OverflowException)                 {                     Console.WriteLine("숫자가 Int32 규격에 맞지 않습니다.");                 }                 Console.Write("다시 하시겠습니까? (Y,N)");                   string go = Console.ReadLine();                 if (go.ToUpper() != "Y")                 {                     repeat = false;                 }               }         }     } }   http://colorscripter.com/info#e" target="_blank" style="color:#e5e5e5text-decoration:none">Colored by Color Scripter