using System; using System.Collections.Generic; using System.Collections; using System.Collections.Specialized; using System.Linq; using System.Text; using System.IO; using System.Reflection; using static System.Math; using System.Numerics; using System.Threading; using System.Runtime.CompilerServices; using System.Diagnostics; //using nint=System.Int32; static class Program{ const int mod=(int)1e9+7; static void Main(){ Sc sc=new Sc(); var s=sc.Ia; var h=new int[s[0]+1]; Uf uf=new Uf(s[1]+1); int ans=0; for(int i = 0;i < s[0];i++) { var e=sc.Ia; if(h[e[1]]==0){h[e[1]]=e[0];} else if(!uf.Same(e[0],h[e[1]])){ uf.Union(e[0],h[e[1]]); ans++; } } Console.WriteLine(ans); } } public class Uf{ private int[] arr,hi; public int all; public Uf(int n){ arr=new int[n]; hi=new int[n]; all=n; for(int i=0;i(int n,Func f){var a=new T[n];for(int i=0;i(int n,Func f){var a=new T[n];for(int i=0;i(int n,Func f){var a=new T[n];for(int i=0;i(int n,Func f){var a=new T[n];for(int i=0;i(){var s=Console.ReadLine().Split();return (Ct(s[0]),Ct(s[1]));} public (T,T,T) Tp3(){var s=Console.ReadLine().Split();return (Ct(s[0]),Ct(s[1]),Ct(s[2]));} public (T1,T1,T2) Tp3(){var s=Console.ReadLine().Split();return (Ct(s[0]),Ct(s[1]),Ct(s[2]));} private T Ct(string s){return (T)Convert.ChangeType(s,typeof(T));} }