#include <iostream>
#include <fstream>
#include <vector>
#define dMAX 100000

using namespace std;

int n, m, a;
int x, y, counter;
vector<int> graf[dMAX + 2];
bool viz[dMAX + 2];

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

void DFS(int v) {
    viz[v] = true;
    int i;
    for (i = 0; i < graf[v].size(); i++) {
        if (!viz[graf[v][i]]) {
            DFS(graf[v][i]);
        }
    }
}

int main()
{
    int i, j;
    fin >> n >> m;
    for (i = 1; i <= m; i++) {
        fin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for (i = 1; i <= n; i++) {
        if (!viz[i]) {
            DFS(i);
            counter++;
        }
    }
    fout << counter << "\n";
    return 0;
}