#include <bits/stdc++.h>
#define NMAX 100005

using namespace std;

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

vector < int > v[NMAX];
bool viz[NMAX];

void dfs ( int x );

int main()
{
    int n, m, i, x, y, nr = 0;

    fin >> n >> m;
    while ( m-- )
    {
        fin >> x >> y;
        v[x].push_back ( y );
        v[y].push_back ( x );
    }

    for ( i = 1 ; i <= n ; i++ ) if ( viz[i] == 0 ) dfs ( i ), nr++;

    fout << nr;

    return 0;
}

void dfs ( int x )
{
    vector < int > :: iterator it;

    viz[x] = 1;
    for ( it = v[x].begin() ; it != v[x].end() ; it++ )
        if ( viz[*it] == 0 )
            dfs( *it );
}