#include <vector>
#include <fstream>

using namespace std;

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

vector < int > gr[100100];
bool used[100100];

void dfs(int nod){
    used[nod] = true;
    for (auto x : gr[nod]){
        if (!used[x]){
            dfs(x);
        }
    }
}

int main()
{
    int n,m;
    in>>n>>m;

    for (int i=1; i<=m; i++){
        int x,y;
        in>>x>>y;
        gr[x].push_back(y);
        gr[y].push_back(x);
    }

    int cont=0;

    for (int s=1;s<=n;s++){
        if (used[s]){
            continue;
        }

        cont++;

        dfs(s);
    }

    out<<cont;

    return 0;
}