#include <bits/stdc++.h>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
vector <int> adjacent [100005];
int visited[100005];
int N, M;
void dfs (int node)
{
    visited[node] = 1;
    for (int i : adjacent[node])
        if (!visited[i])
            dfs (i);
}
int main ()
{
    fin >> N >> M;
    for (int i = 1; i <= M; i++)
    {
        int x, y;
        fin >> x >> y;
        adjacent[x].push_back (y);
        adjacent[y].push_back (x);
    }
    int conex_parts = 0;
    for (int i = 1; i <= N; i++)
        if (!visited[i])
        {
            conex_parts++;
            dfs (i);
        }
    fout << conex_parts;
}