#include <bits/stdc++.h>
#define NMAX 100001

using namespace std;

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

vector<int> V[NMAX];
int n, m, componente;
bool used[NMAX];

void DFS(int nod) {
    used[nod] = 1;
    for(int i = 0; i < V[nod].size(); i++) {
        if(!used[V[nod][i]]) DFS(V[nod][i]);
    }
}

int main()
{
    fin >> n >> m;
    int a, b;
    while(m--) {
        fin >> a >> b;
        V[a].push_back(b);
        V[b].push_back(a);
    }
    for(int i = 1; i <= n; i++) {
        if(!used[i]) {
            DFS(i);
            componente++;
        }
    }
    fout << componente << '\n';
    return 0;
}