#include <bits/stdc++.h>
using namespace std;

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

int n;
vector < int > v[100005];
int viz[100005];
int m;
int x,y;
int nrcompconex;

int dfs(int nod) {
    viz[nod]=1;
    for (int k=0;k<v[nod].size();k++) {
        int nodtoviz = v[nod][k];
        if (viz[nodtoviz]==0) {
            dfs(nodtoviz);
        }
    }
}

int main()
{
    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);
            nrcompconex++;
        }
    }
    g << nrcompconex;
    return 0;
}