#include <bits/stdc++.h>

using namespace std;

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

int n, m;
vector <int> vecini[100001];
bitset <100001> viz;
void dfs(int i)
{
    viz[i] = 1;
    for (auto j : vecini[i])
        if (viz[j] == 0)
            viz[j] = 1, dfs(j);
}

int main()
{
    f>>n>>m;
    for (int i=1;i<=m;i++)
    {
        int x, y;
        f>>x>>y;
        vecini[x].push_back(y);
        vecini[y].push_back(x);
    }

    int cnt = 0;
    for (int i=1;i<=n;i++)
        if (viz[i] == 0)
            dfs(i), cnt++;

    g<<cnt;
}