#include <fstream>
#include <vector>
using namespace std;

ifstream is("dfs.in");
ofstream os("dfs.out");

int n, m;
vector<vector<int>> G;
vector<bool> s;
int cnt, x, y;

void Dfs(int k);

int main()
{
    is >> n >> m;
    G.resize(n+1);
    s.resize(n+1);
    for ( int i = 1; i <= m; i++ )
    {
        is >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for ( int i = 1; i <= n; i++ )
        if ( s[i] == false )
        {
            cnt++;
            Dfs(i);
        }
    os << cnt;

    is.close();
    os.close();
    return 0;
}

void Dfs( int k )
{
    s[k] = true;
    for ( const auto& y : G[k] )
        if ( s[y] == false )
            Dfs(y);
}