#include <bits/stdc++.h>

#define NMAX (100005)

using namespace std;

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

vector<int> vecini[NMAX];
int n, m, x, y, nr;
bool viz[NMAX];

void dfs(int x)
{
    viz[x] = true;
    for (int i = 0; i < vecini[x].size(); i++)
    {
        int y = vecini[x][i];
        if (!viz[y])
            dfs(y);
    }
}

int main()
{
    f >> n >> m;
    while (m--)
    {
        f >> x >> y;
        vecini[x].push_back(y);
        vecini[y].push_back(x);
    }

    for (int i = 1; i <= n; i++)
    {
        if (!viz[i])
        {
            nr++;
            dfs(i);
        }
    }

    g << nr;

    return 0;
}