#include <fstream>
#include <vector>

#define N 100005

using namespace std;

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

vector <int> v[N];
bool f[N];

inline void DFS(int x)
{
    f[x] = 1;
    vector <int>::iterator it;
    for(it = v[x].begin(); it != v[x].end(); ++it)
        if(!f[*it]) DFS(*it);
}

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

    int ct = 0;
    for(int i = 1; i <= n; ++i)
        if(!f[i])
        {
            DFS(i);
            ct++;
        }
    fout << ct;
    fout.close();
    return 0;
}