#include <bits/stdc++.h>
#include <fstream>

using namespace std;

int graph[1005][1005];
int n, m;
int vis[1005];

void dfs(int node)
{
    vis[node] = true;
    for (int i = 1; i <= n; ++i)
        if (graph[node][i])
            dfs(i);
}

int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin >> n >> m;
    for (int i = 1; i <= m; ++i)
    {
        int x, y;
        fin >> x >> y;
        graph[x][y] = 1;
        graph[y][x] = 1;
    }

    int cc = 0;
    for (int i = 1; i <= n; ++i)
        if (!vis[i])
        {
            dfs(i);
            cc++;
        }

    fout << cc;
}