#include <bits/stdc++.h>
using namespace std;

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

const int NMAX=100005;

int N,M,x,y;

vector < int > Ad[NMAX];

int viz[NMAX];

void read()
{
    fin>>N>>M;

    for(int i=1;i<=M;++i)
    {
        fin>>x>>y;

        Ad[x].push_back(y);
        Ad[y].push_back(x);
    }
}

void dfs(int u)
{
    int w;

    viz[u]=1;

    for(int i=0;i<Ad[u].size();++i)
    {
        w=Ad[u][i];

        if(viz[w]==0)
        {
            dfs(w);
        }
    }
}

void solve()
{
    int nr=0;

    for(int i=1;i<=N;++i)
        if(viz[i]==0)
        {
            nr++;
            dfs(i);
        }

    fout<<nr;

}

int main()
{
    read();
    solve();
    return 0;
}