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

using namespace std;

ifstream f("dfs.in");/// !!! chg to dfs.in /out
ofstream g("dfs.out");

vector <int> G[100010];
bool vizitat[100010];

void dfs(int i)
{
    if(vizitat[i]) return;
    vizitat[i] = 1;
    for(int j = 0; j < G[i].size();j++)
    {
        dfs(G[i][j]);
    }
}

int main()
{
    ///citire
    int N, M;
    f >> N >> M;
    int X;
    for(int i = 0; i < M ; i++)
    {
        int x,y;
        f >> x >> y;

        G[x].push_back(y);
        G[y].push_back(x);

    }

    ///Rez:
    int sol = 0;
    for (int i = 1; i <= N; i++)
    {
        if(!vizitat[i])
        {
            dfs(i);
            sol++;
        }
    }

    g << sol;

    return 0;
}