#include <fstream>
#include <vector>
#include <string.h>

using namespace std;

#define lim 100001




vector<int> G[lim];
bool vizitat[lim];
int N,M;


void dfs(int startNode)
{
    vizitat[startNode] = true;

    for(auto node : G[startNode])
        if(vizitat[node] == 0)
            dfs(node);

}
int main() {

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

    int x,y;
    int count = 0;
    fin>>N>>M;

    for(int i = 1 ; i  <= M; i++)
    {

        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);

    }



    for(int i = 1; i <= N; i++)
        if(vizitat[i] == 0)
        {
            dfs(i);
            count++;
        }

    fout<<count;

    fin.close();
    fout.close();
    return 0;
}