#include <iostream>
#include <fstream>
#include <vector>
#define N_MAX 100001

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");

vector <int> v[N_MAX];
bool visited[N_MAX];
int cc = 0, N, M;

void DFS(int node)
{

    for(int i = 0; i < v[node].size(); i++)
    {
        //cout<<i<<endl;
        if(!visited[v[node][i]])
        {
            visited[v[node][i]] = true;
            DFS(v[node][i]);
        }
    }
}

int main()
{
    in >> N >> M;
    for(int i = 0; i < M; i++)
    {
        int x, y;
        in >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i = 0; i < N; i++)
    {
        if(!visited[i])
        {
            visited[i] = true;
            DFS(i);
            cc++;
        }

    }
    out<<cc;
    return 0;
}