#include <bits/stdc++.h>

using namespace std;

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

vector<int> adj[100005];
int viz[100005];
int n;

void dfs(int x)
{
    viz[x] = 1;
    for(int y : adj[x])
    {
        if(viz[y] == 0)
            dfs(y);
    }
}

int main()
{
    int x, y, m, i, cnt = 0;
    f >> n >> m;
    for(i = 1; i <= m; i++)
    {
        f >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    for(i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            dfs(i);
            cnt++;
        }
    }

    g << cnt;
    return 0;
}