#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

const int NMAX=1e5+5;
int viz[NMAX];
vector<int>v[NMAX];

void dfs(int poz)
{
    viz[poz]=1;
    for(auto i:v[poz])
    {
        if(viz[i]==0)
            dfs(i);

    }
}

int main()
{
    int n,m,i,y,x,kon=0;
   fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(viz[i]==0)
            dfs(i),kon++;
    fout<<kon;
    return 0;
}