#include <bits/stdc++.h>
#define N_MAX 100005

using namespace std;

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

int N, M, vis[N_MAX], comp;

vector < int > G[N_MAX];

void DFS(int currNode)
{
    for (int node: G[currNode])
        if (vis[node] == 0)
        {
            vis[node] = 1;
            DFS(node);
        }
}

int main()
{
    fin >> N >> M;
    for (int i = 1; i <= M; i++)
    {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

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

    fout << comp;
    return 0;
}