#include <bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int> viz;
int n, m, s,d,nr=0;
bool ok;
vector<vector<int> > a;

void citire()
{
    int x, y, i;
    f >> n >>m;
    for(i=0; i<=n; i++)
        viz.push_back(0);

    while(f>>x>>y)
    {
        a[x].push_back(y);
        a[y].push_back(x);
    }


}
void dfs(int X)
{
    viz[X] = 1;
    for( auto itr: a[X])
        if(  viz[itr] == 0) dfs(itr);
}
int main()
{
    citire();
    for( int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            nr++;
        }
    }
    g<<nr;
    return 0;
}