#include <bits/stdc++.h>
#define NMAX 100003
using namespace std;
ifstream f ("dfs.in");
ofstream g ("dfs.out");
vector <int> q[NMAX];
int  i , j , n , m , x , y ;
bool viz[NMAX] ;
int Sol = 0 ;
void dfs(int s)
{
    viz[s] = true ;
    int length = q[s].size() ;
    for (int j  = 0 ; j < length ; j ++)
    {
        if (viz[q[s][j]] != true) dfs(q[s][j]);
    }
}
int main()
{
    f >> n >> m ;
    for (i = 1 ;  i <= m ; i++)
    {
        f >> x >> y;
        q[x].push_back(y) ;  //x->y
        q[y].push_back(x) ; //y->x
        //Graf NEORIENTAT x <-> y
    }
    for (i = 1  ; i <= n ; i ++)
    {
        if (viz[i] != true)
            {Sol ++ ;dfs(i);}
    }
    g << Sol ;
    return 0 ;

}