#include <fstream>
#include <vector>
#define Nmax 100001
using namespace std;

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

int n, m, fv[ Nmax ], nrc;
vector < int > v[ Nmax ];

void dfs( int nod )
{
    fv[ nod ] = 1;

    for ( int i = 0; i < (int)v[ nod ].size(); ++ i )
        if ( not fv[ v[ nod ][ i ] ] )
           dfs( v[ nod ][ i ] );
}

int main()
{
    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 );
    }

    for ( int i = 1; i <= n; ++ i )
        if ( not fv[ i ] )
        {
            nrc ++;
            dfs( i );
        }
    g << nrc;
    return 0;
}