#include <fstream>
#include <vector>
using namespace std;

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

int N, M; //nodes, edges
int ConexComps;

vector <int> Graph[100001]; //graph
bool Visited[100001];

void Read();
void DFS(int Node);

int main()
{
    Read();

    for (int i = 1; i <= N; ++i)
        if (Visited[i] == 0)
        {
            ConexComps++;
            DFS(i);
        }

    os << ConexComps << '\n';

    is.close();
    os.close();
}

void Read() //graph input
{
    is >> N >> M;
    for (int x, y; M; --M)
    {
        is >> x >> y;
        Graph[x].push_back(y);
        Graph[y].push_back(x);
    }
};

void DFS(int Node)  //Depth First Search
{
    Visited[Node] = 1;
    for (const int& Next : Graph[Node])
        if (Visited[Next] == 0)
            DFS(Next);
};