#include <iostream>
#include <vector>
#include <queue>
#include <stack>
#include <fstream>

#define NMAX 1000000

using namespace std;
int viz[100100];
vector <int> graf[NMAX];

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

void DFS(int x)
{
    viz[x] = 1;
    for(unsigned int i = 0; i < graf[x].size(); i++)
        if(!viz[graf[x][i]])
            DFS(graf[x][i]);
}

int main()
{
    int n,m,nr=0;
    int x,y;

    f>>n>>m;

    for(int i = 0; i < m; i++)
    {
        f>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }


    for(int i=1; i<=n; i++)
        if(viz[i]==0) DFS(i), nr++;
    g<<nr;

    return 0;
}