#include <fstream>

using namespace std;

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

const int N = 100001;
const int M = 2*N;
int lst[N], vf[2*M], urm[2*M], nr;
int n, m, x, y, ncomp;
bool viz[N];

void adauga(int x, int y){
    vf[++nr] = y;
    urm[nr] = lst[x];
    lst[x] = nr;
}

void dfs(int x){

    viz[x]=true;
    for (int p=lst[x];p!=0;p=urm[p])
    {
        int y=vf[p];
        if (!viz[y]) dfs(y);
    }
}

int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        adauga(x, y);
        adauga(y, x);
    }
    for(int i=1; i<=n; i++)
    {
        if(viz[i] == 0)
        {
            ncomp++;
            dfs(i);
        }
    }
    out<<ncomp;
    return 0;
}