#include <fstream>
#include <vector>

using namespace std;

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

int N, M, marcat[100001];

vector <int> G[100001];

void dfs(int x)
{
    marcat[x] = 1;

    for (int i = 0; i < G[x].size(); i++)
    {
        if (!marcat[ G[x][i] ])
            dfs(G[x][i]);
    }
}

int main()
{
    in >> N >> M;

    for (int i = 1; i <= M; i++)
    {
        int x, y;
        in >> x >> y;

        G[x].push_back(y);
        G[y].push_back(x);
    }
    int contor = 0;
    for (int i = 1; i <= N; i++)
    {
        if (! marcat[i])
        {
            dfs(i);
            contor++;
        }
    }

    out << contor;

    return 0;
}