#include <fstream>
#include <vector>
using namespace std;

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

vector <vector<int>> links;
bool visited[100001];

void DFS(int x){
    for( int i = 0; i < links[x].size(); i++)
        if(!visited[links[x][i]])
        {
            visited[links[x][i]] = 1;
            DFS(links[x][i]);
        }
}

int main()
{
    int n, m;
    fin >> n >> m;
    links.resize(n + 1);

    int x, y;
    while( m-- )
    {
        fin >> x >> y;
        links[x].push_back(y);
        links[y].push_back(x);
    }

    int components = 0;
    for( int i = 1; i <= n; ++ i )
        if(!visited[i]){
            components++;
            visited[i] = 1;
            DFS(i);
        }
    fout << components;

    return 0;
}