#include <cstdio>
#include <vector>
using namespace std;

#define Nmax 100002

FILE *f = fopen ( "dfs.in", "r" );
FILE *g = fopen ( "dfs.out", "w" );

vector < int > G[Nmax];
bool viz[Nmax];

void DFS ( int nod ){

    viz[nod] = 1;

    vector < int > :: iterator it;

    for ( it = G[nod].begin(); it < G[nod].end(); ++it )
        if ( !viz[*it] )
            DFS ( *it );
}

int main(){

    int N, M, x, y, CompConexe = 0;

    fscanf ( f, "%d%d", &N, &M );

    for ( int i = 1; i <= M; ++i ){
        fscanf ( f, "%d%d", &x, &y );
        G[x].push_back ( y );
        G[y].push_back ( x );
    }

    for ( int i = 1; i <= N; ++i ){
        if ( !viz[i] ){
            CompConexe++;
            DFS ( i );
        }
    }

    fprintf ( g, "%d", CompConexe );

    return 0;
}