#include<fstream>
#include<vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int nmax =100002;
bool viz[nmax];
vector <int> a[nmax];
void dfs( int nod ) 
{
    viz[nod] = 1;
    for( int i = 0; i <(int)a[nod].size(); ++ i ) 
	{
        if ( viz[ a[nod][i] ] == 0 )
            dfs( a[nod][i] );
    }
 
}
int main()
{
    int n, m, x, y, sol;
    fin>>n>>m;
    sol = 0;
    for( int i = 0; i < m; ++ i ) 
	{
        fin>>x>>y;
        a[x].push_back( y );
        a[y].push_back( x );
    }
    for ( int i = 1; i <= n; ++ i ) 
	{
        if ( viz[i] == 0 ) 
		{
            dfs( i );
            ++sol;
        }
    }
    fout<<sol<<endl;
    fin.close();
    fout.close();
    return 0;
}