#include <fstream>
#include <vector>
#define N 100005
using namespace std;

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

int n, m, p[ N ];
vector < int > v[ N ];

void citire()
{
    int x, y;

    f >> n >> m;


    for ( int i = 1; i <= m; ++ i )
    {
        f >> x >> y;
        v[ x ].push_back ( y );
        v[ y ].push_back ( x );
    }
}

void DFS (int nod)
{
    p[ nod ] = 1;
    for ( int j = 0; j < ( int )v[ nod ].size(); ++ j )
    {
        if ( not p[v[ nod ][ j ]] )
            DFS ( v[ nod ][ j ] );
    }
}

int main()
{
    int nrcomp = 0;

    citire();

    for ( int i = 1; i <= n; ++ i )
        if ( not p[ i ] )
        {
            nrcomp ++;
            DFS ( i );
        }

    g << nrcomp;
    return 0;
}