#include <fstream>
#include <vector>

#define u_int unsigned int

using namespace std;

vector<vector<u_int> > L(50000 + 1);
vector<bool> viz(50000 + 1);

void travad(u_int i)
{
    viz[i] = 1;
    for(int j = 0; j < L[i].size(); j++)
    {
        if(viz[L[i][j]] == false)
        {
            travad(L[i][j]);
        }
    }
}

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