#include <fstream>
#include <vector>

using namespace std;

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

void DFS(int x);

int n, m, x, nr, uz[100005];
vector<int> L[100005];

int main()
{
    int i, j, x, y, c;

    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 (!uz[i])
        {
            DFS(i);
            nr++;
        }
    fout << nr << '\n';
    return 0;
}

void DFS(int x)
{
    int i;

    uz[x] = 1;
    for (i=0;i<L[x].size();i++)
        if (!uz[L[x][i]])
            DFS(L[x][i]);
}