#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

#define N 100005

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

int n, m, sol;
bool viz[N];
vector <int> a[N];

void DFS(int x)
{
    viz[x] = 1;
    for(int i=0; i<a[x].size(); i++)
        if(!viz[a[x][i]]) DFS(a[x][i]);
}

int main()
{
    fin>>n>>m;
    int x, y;
    while(m--)
    {
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    for(int i=1; i<=n; i++)
        if(!viz[i])
        {
            sol++;
            DFS(i);
        }

    fout<<sol;
    return 0;
}