#include <iostream>
#include <fstream>
#include <vector>
#define N 100010

using namespace std;

vector<int> l[N];
bool visited[N];
int sizes[N];

void DFS(int node)
{
    visited[node]=1;
    for (int i=0; i<sizes[node]; i++)
        if (!visited[l[node][i]])
        {
            visited[l[node][i]]=1;
            DFS(l[node][i]);
        }
}

int main()
{
    int n, m, x, y, nr=0;
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin >> n >> m;
    for (int i=1; i<=m; i++)
    {
        fin >> x >> y;
        l[x].push_back(y);
        l[y].push_back(x);
    }
    for (int i=1; i<=n; i++)
        sizes[i]=l[i].size();
    for (int i=1; i<=n; i++)
        if (!visited[i])
        {
            DFS(i);
            nr++;
        }
    fout << nr;
    return 0;
}