#include <fstream>
#include <vector>

using namespace std;

const int NMAX= 100000;

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

vector <int> g[NMAX+1];
bool v[NMAX+1];

void dfs( int nod )
{
    v[nod]= 1;
    for( int i=0; i<(int)g[nod].size(); ++i )
    {
        if( v[g[nod][i]]==0 ) dfs( g[nod][i] );
    }
}

int main(  )
{
    int N, M;
    in >> N >> M;
    for( int i= 1; i<=M; ++i )
    {
        int x, y;
        in >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int NR= 0;
    for( int i= 1; i<=N; ++i )
    {
        if( v[i]==0 )
        {
            dfs( i );
            ++NR;
        }
    }

    out << NR << '\n';

    return 0;
}