using System; using System.Collections.Generic; using System.Linq; namespace PracticeAtCoder { class Program { static void Main(string[] args) { //1-10 string sC = Console.ReadLine(); string[] sD = sC.Split(' '); int[] after = sD.Select(s => int.Parse(s)).ToArray(); int flg = 0 ; int intA = 0; int intB=0; for(int i=0; i<9;i++){ intA = after[i]; intB = i+1; if(intA != intB){ flg = i+1; Console.WriteLine(flg); break; } } } } }