#include <fstream>
#include <vector>
using namespace std;
ifstream is ("dfs.in");
ofstream os ("dfs.out");
vector <int> v[100001];
int n, m, nod, viz[100001], cnt;
void Read();
void Conex(int x);
int main()
{
    Read();
    for(int i = 1; i <= n; ++i)
        if(viz[i] == 0)
        {
            Conex(i);
            cnt++;
        }
    os << cnt;

    return 0;
}
void Read()
{
    int x, y;
    is >> n >> m;
    for(int i = 1; i <= m; ++i)
    {
        is >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}
void Conex(int x)
{
    viz[x] = 1;
    for(int i = 0; i < v[x].size(); ++i)
    {
        if(!viz[v[x][i]])
            Conex(v[x][i]);
    }
    v[x].clear();
    return;
}