#include <bits/stdc++.h>

using namespace std;

const int NMAX = 1e5;
vector <int> v[NMAX + 5];
bool f[NMAX + 5];

void dfs(int nod) {
    f[nod] = 1;
    for (int i = 0;i < v[nod].size();i++) {
        if (!f[v[nod][i]])
            dfs(v[nod][i]);
    }
}
int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    int n,m,x,y,cnt = 0;
    fin >> n >> m;
    for (int i = 0;i < m;i++) {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (int i = 1;i <= n;i++)
        if (!f[i]) {
            dfs(i);
            cnt++;
        }
    fout << cnt;
    return 0;
}