#include <fstream>
#include <vector>

#define NMax 100010

using namespace std;

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

vector<int> G[NMax];

int nodes, edges, n1, n2, conex;
bool mark[NMax];

void dfs(int node)
{
    for (vector<int>::iterator it = G[node].begin(); it != G[node].end(); it++) {
        if (!mark[*it]) {
            mark[*it] = true;
            dfs(*it);
        }
    }
}

int main()
{
    f>>nodes>>edges;

    for (int i=1; i<=edges; i++) {
        f>>n1>>n2;

        G[n1].push_back(n2);
        G[n2].push_back(n1);
    }

    for (int node=1; node<=nodes; node++) {
        if (!mark[node]) {
            mark[node] = true;
            conex++;
            dfs(node);
        }
    }

    g<<conex;

    return 0;
}