#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

const int NMAX = 100005;
vector <int> g[NMAX + 5];
vector <int> viz;
#define white 0
#define gray 1
#define black 2
int n;

void dfs(int u)
{
    viz[u] = gray;
    for(int j = 0; j < (int)g[u].size(); ++j)
    {
        int v = g[u][j];
        if(viz[v] == white)
            dfs(v);
    }
    viz[u] = black;
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int m; cin >> n >> m;

    for(int i = 1; i <= m; ++i)
    {
        int u, v; scanf("%d%d", &u, &v);
        g[u].push_back(v);
        g[v].push_back(u);
    }

    viz.assign(n + 1, white);
    int ans = 0;
    for(int i = 1; i <= n; ++i)
    {
        if(viz[i] == white)
        {
            ans++;
            dfs(i);
        }
    }

    cout << ans;
    return 0;
}