#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 100010

using namespace std;

vector <int> edges[NMAX];
bool visited[NMAX];

void dfs(int vertix)
{
    visited[vertix] = 1;
    for (auto it : edges[vertix])
        if (!visited[it])
            dfs(it);
}

int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    int n, m, x, y, nr = 0;
    fin >> n >> m;
    for (int i=1; i<=m; i++)
    {
        fin >> x >> y;
        edges[x].push_back(y);
        edges[y].push_back(x);
    }
    for (int i=1; i<=n; i++)
    {
        if (!visited[i])
        {
            nr++;
            dfs(i);
        }
    }
    fout << nr;
    return 0;
}