/**
  DFS recursiv
*/
#include <iostream>
#include <cstdio>
#include <cstring>
#include<vector>
#include<stack>
using namespace std;

vector <int>lv[100000];
vector <int>::iterator ii;
bool used[100000];

void DFS(int nodc)
{

    vector <int>::iterator ii;
    for(ii=lv[nodc].begin();ii!=lv[nodc].end();++ii)
        if(!used[*ii])
        {
            used[*ii]=1;
            DFS(*ii);
        }
}

int main()
{
    FILE *f=fopen("dfs.in","r"); FILE *g=fopen("dfs.out","w");
    int n,m,i,x,y;
    fscanf(f,"%d%d",&n,&m);
    memset(used,0,sizeof(used));
    for(i=1;i<=m;i++)
    {
        fscanf(f,"%d%d",&x,&y);
        lv[x].push_back(y);
        lv[y].push_back(x);
    }
    int ok=0;

    for(i=1;i<=n;i++)
    { if(used[i]==0){DFS(i); ok++;};


    }


    fprintf(g,"%d",ok);
    return 0;
}