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

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

int n, m, x, y, k;
vector<vector<int>> G;
vector<bool> V;

void Read();
void DFS( int i );
int main()
{
    Read();

    for ( int i = 1; i <= n; i++ )
        if ( !V[i] )
        {
            k++;
            DFS(i);
        }
    os << k;

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

void Read()
{
    is >> n >> m;
    G = vector<vector<int>>(n+1);
    V = vector<bool>(n+1);
    for ( int i = 1; i <= m; i++ )
    {
        is >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS( int i )
{
    V[i] = true;
    int j;
    for ( int a = 0; a < G[i].size(); a++ )
    {
        j = G[i][a];
        if ( !V[j] )
            DFS(j);
    }
}