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

using namespace std;

vector<vector<int> > L(50000 + 1);
bool viz[50000 + 1];
int n, m;
int cc;

void travad(int i)
{
    viz[i] = 1;
    for(std::vector<int>::iterator it = L[i].begin(); it != L[i].end(); ++it)
        if (viz[*it] == false)
            travad(*it);
}

int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            cc++;
            travad(i);
        }
    }
    fout << cc;
    return 0;
}