#include <bits/stdc++.h>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

int n,m,a[1001][1001],v[1001];
int i,j,dr,nr;

void citire(){
    f>>n>>m;
    for(int k=1;k<=m;k++){
        f>>i>>j;
        a[i][j]=a[j][i]=1;
    }
}

void DFS(int nod){
     v[nod]=1;

    for(int j=1;j<=n;j++)
        if(a[nod][j]==1 && v[j]==0)
            DFS(j);
}




int main()
{
    citire();
    for(int i=1;i<=n;i++)
       if(!v[i]){nr++; DFS(i);}


       g<<nr;
    return 0;
}