#include <fstream>
#include <vector>
#define MAX 100010
using namespace std;

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

int n, m, cnt;
bool nv[MAX];
vector<int> G[MAX];

void Read();
void DFS( int nod );

int main()
{
    Read();
    for ( int i = 1; i <= n; ++i )
        if ( !nv[i] )
        {
            DFS(i);
            cnt++;
        }
    os << cnt;

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

void Read()
{
    is >> n >> m;
    int x, y;
    while ( m -- )
    {
        is >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS( int nod )
{
    nv[nod] = true;
    for ( const auto i:G[nod] )
        if ( !nv[i] )
            DFS(i);
}