#include <bits/stdc++.h>

using namespace std;

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

int n, m;
vector <int> ad[100005];
int viz[100005];

void DFS(int nod)
{
    viz[nod] = 1;
    for(int e : ad[nod])
        if(viz[e] == 0)
            DFS(e);
}

int main()
{
    int x, y;
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        ad[x].push_back(y);
        ad[y].push_back(x);
    }
    x = 0;
    for(int i = 1; i <= n; i++)
        if(viz[i] == 0)
        {
            x++;
            DFS(i);
        }
    fout << x << '\n';
    return 0;
}