#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 100005;

int n, m, cont;
bool v[NMAX];
vector < int > a[NMAX];

void read()
{
    int x, y;
    fin >> n >> m;
    for(int i = 1; i <= m; i ++)
    {
        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

void dfs(int k)
{
    v[k] = true;
    for(auto i : a[k])  ///int i = 1; i < a[k].size(); i ++ - de ce nu merge?
    {
        if(v[i] == 0)
            dfs(i);
    }
}

void solve()
{
    for(int i = 1; i <= n; i ++)
    {
        if(v[i] == 0)
        {
            cont++;
            dfs(i);
        }
    }
    fout << cont;
}

int main()
{
    read();
    solve();
    return 0;
}