#include <fstream>
#include <vector>
#include <queue>

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

queue< int >q;
vector< int >A[ 100005 ];
vector< int >:: iterator itt;

int C[ 100005 ], viz[ 100005 ], rasp, i, N, M, start, nodc, nodn, x, y;

void DFS( int nod )
{
    viz[ nod ] = 1;
    for ( auto it:A[ nod ] )
    {
        if ( viz[ it ] == 0 )
            DFS( it );
    }
}

int main()
{
    fin >> N >> M;
    for( i = 1; i <= M; i++ )
    {
        fin >> x >> y;
        A[ x ].push_back( y );
        A[ y ].push_back( x );
    }
    for( i = 1; i <= N; i++ )
    {
        if ( viz[ i ] == 0 )
        {
            rasp++;
            DFS( i );
        }
    }
    fout<< rasp;
}