#include <bits/stdc++.h>

std :: ifstream in ("dfs.in");

std :: ofstream out ("dfs.out");

const int NMAX = 1e5 + 5;

int n;

int m;

int x;

int y;

int cnt;

std :: vector <int> v[NMAX];

std :: bitset <NMAX> visited;

void dfs(int nod)
{

    visited[nod] = true;

    for(int i : v[nod])
    {
        if(!visited[i])
        {
            dfs(i);
        }
    }
}

int main()
{

    in >> n >> m;

    for(int i = 1; i <= m; i ++)
    {
        in >> x >> y;

        v[x].push_back(y);

        v[y].push_back(x);
    }

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

    out << cnt;

    return 0;
}