#include <fstream>
#include <vector>

using namespace std;

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

vector<int> v[100010];
int vaz[100010];
int n,m,x,y,sol=0;

void dfs(int nod)
{
    vaz[nod]=1;
    for ( int i = 0 ; i < v[nod].size() ; i ++ )
      if( vaz[ v[nod][i] ] == 0 )
        dfs(v[nod][i]) ;
}

int main()
{
    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 ( vaz[i] == 0 )
        {
            sol ++;
            dfs(i);
        }
    g << sol;
    return 0;
}