#include <iostream>
#include <fstream>
#include <vector>


using namespace std;

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

const int MAXN = 100001;

int N, M, visited[MAXN], nr;
vector<int> G[MAXN];

void DFS(int nod)
{
    visited[nod] = 1;
    for (auto elem : G[nod])
        if (!visited[elem])
            DFS(elem);
}
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);

    }
    for (int i = 1; i <= N; i++)
        if (!visited[i])
        {
            nr++;
            DFS(i);
        }
    out<<nr<<"\n";
    return 0;
}