#include <cstdio>
#include <vector>
#include <fstream>

using namespace std;

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

#define NMAX 100001

vector<int> a[NMAX];
int viz[NMAX], n, m, rez;

void dfs(int x)
{
    int y;

    viz[x] = rez;
    for(unsigned int i = 0; i < a[x].size(); i++)
    {
        y = a[x][i];
        if(!viz[y])dfs(y);
    }
}

int main()
{
    int x, y;

    fin >> n >> m;

    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

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

    fout << rez;
    return 0;
}