#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
#define nmax 100005
vector <int> m[nmax];
bool viz[nmax];
int n, nm, nc=0;
void dfs(int nod)
{
    viz[nod]=true;
    for(unsigned int i=0; i<m[nod].size();i++)
    {
        int vec=m[nod][i];
        if(!viz[vec])dfs(vec);
    }
}
void citire()
{
    int i, x, y;
    in>>n>>nm;
    for(i=1;i<=nm;i++)
    {
        in>>x>>y;
        m[x].push_back(y);
        m[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            nc++;
            dfs(i);

        }
    }
}
int main()
{

    citire();
    out<<nc;
    return 0;
}