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

#define MAX 100001

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

int n , m , nr , x , y;
vector < int > G[MAX];
bool used[MAX];

void dfs ( int i )
{
    used [ i ] = true;
    for ( vector < int > ::iterator j = G[i].begin() ; j != G[i].end() ; j++ )
    {
        if (! used[ (*j) ] )
            dfs( (*j ) ) ;
    }
}


int main()
{
    f >> n >> m;
    for ( ; m-- ; )
    {
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for ( int i = 1;  i <= n ; i++ )
    {
        if ( !used[i] )
        {
            dfs(i);
            nr++;
        }
    }

    g << nr;

    return 0;
}