#include <bits/stdc++.h>

using namespace std;

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

int n, m;

int viz[100001];

vector <int> graf[100001];

void dfs(int i)
{
    viz[i] = 1;
    for(int j = 0; j < graf[i].size(); j++)
    {
        if(!viz[graf[i][j]])
            dfs(graf[i][j]);
    }
}

int main()
{
    in >> n >> m;
    int l, c;
    while(m--)
    {
        in >> l >> c;
        graf[l].push_back(c);
        graf[c].push_back(l);
    }
    int cnt = 0;
    for(int i = 1; i <= n; i++)
    {
        if(!viz[i])
        {
            dfs(i);
            cnt++;
        }
    }
    out << cnt;
    return 0;
}