#include <fstream>
#include <vector>

using namespace std;

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

int n,m,i,nr,x,y,v[100005];
vector<int> L[100005];

void dfs(int nod)
{
    v[nod] = 1;
    for (int i=0; i<L[nod].size(); i++)
    {
        int vecin = L[nod][i];
        if (!v[vecin])
            dfs(vecin);
    }
}

int main()
{
    fin >> n >> m;
    for (i=1; i<=m; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for (i=1; i<=n; i++)
        if (!v[i])
        {
            dfs(i);
            nr++;
        }
    fout << nr;
    return 0;
}