#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

bool viz[200000];
int m, n;
vector <int> a[200000];

void citire()
{
    int x, y;
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

void dfs(int x)
{
    viz[x]=true;
    int y;
    for(size_t i=0;i<a[x].size();i++)
    {
        y=a[x][i];
        if(!viz[y]) dfs(y);
    }
}

int main()
{
    citire();
    int nr=0,i;
    for(i=1;i<=n;i++)
        if(!viz[i])
        {
            dfs(i); nr++;
        }
    out<<nr;
    return 0;
}