#include <bits/stdc++.h>

using namespace std;

ifstream f("in");
ofstream g ("out");
vector <int>v[100005];
int viz[100005];

void DFS(int nod)
{

       viz[nod] = 1;
       for(int i = 0; i < v[nod].size(); i++)
        if(viz[v[nod][i]] == 0)
        DFS(v[nod][i]);

}

int main()
{
    int n,m,x,y,k=0;
    f>>n>>m;
    for(int i = 1; i <= m; i++)
    {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            DFS(i);
            k++;
        }
    }
    g << k;
    return 0;
}