#include <iostream>
#include <fstream>
#include <vector>
#define MAX 5000005
using namespace std;

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

int nrnod, nrmuchii;
int viz[MAX];
vector<int> v[MAX];

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

int main()
{
    int comp=0, x, y;
    f>>nrnod>>nrmuchii;
    for(int i=1; i<=nrmuchii; i++)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=nrnod;i++)
        if(!viz[i])
        {
            dfs(i);
            comp++;
        }
    g<<comp<< " ";

    return 0;
}