#include <bits/stdc++.h>

using namespace std;

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

int n, m;

typedef struct nod
{
    int info;
    nod * a;
}*vnod;
vnod v[100005];

int viz[100005];

void adauga(vnod &dest, int val)
{
    vnod p;
    p = new nod;
    p -> info = val;
    p -> a = dest;
    dest = p;
}

void dfs(int x)
{
    vnod p;
    viz[x] = 1;
    for(p = v[x]; p != NULL; p = p -> a)
    {
        if(!viz[p->info])
        {
            dfs(p->info);
        }
    }
}

int main()
{
    in >> n >> m;
    int x, y;
    for(int i = 1; i <= m; i++)
    {
        in >> x >> y;
        adauga(v[x], y);
        adauga(v[y], x);
    }
    int cnt = 0;
    for(int i = 1; i <= n; i++)
    {
        if(!viz[i])
        {
            cnt++;
            dfs(i);
        }
    }
    out << cnt;
    return 0;
}