#include <fstream>
#include <vector>

using namespace std;

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


const int NMAX = 100005;

vector < int > edges[NMAX];
int n, m, isles = 0;
bool visited[NMAX];

void DFS(int node)
{
    visited[node] = true;
    for (unsigned int i = 0; i < edges[node].size(); i++){
        int neighbour = edges[node][i];
        if (!visited[neighbour])
            DFS(neighbour);
    }
}

void read()
{
    fin >> n >> m;
    for (int i = 1; i <= m; i++){
        int x, y;
        fin >> x >> y;
        edges[x].push_back(y);
        edges[y].push_back(x);
    }
    for (int i = 1; i <= n; i++)
        if (!visited[i]){
            isles++;
            DFS(i);
        }
}

int main()
{
    read();
    fout << isles;
    return 0;
}