#include <iostream>
#include <fstream>
#include <list>
#define Maxx 100001
using namespace std;
list <int> A[Maxx];
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int VIZ[Maxx],j,n,m,x,y,conex;
void dfs(int k)
{
    int node=k;
    VIZ[k]=1;
    list <int> :: iterator it;
    for (it=A[node].begin(); it!=A[node].end(); ++it)
    {
        node=(*it);
        if (!VIZ[node])
            dfs(node);
    }
}
int main()
{
    fin>>n>>m;
    for (int i=1; i<=m; i++)
    {
        fin>>x>>y;
        A[x].push_back(y);
        A[y].push_back(x);
    }
    for (int i=1; i<=n; i++)
    {
        if (!VIZ[i])
        {
            dfs(i);
            conex++;
        }
    }
    fout<<conex;
    return 0;
}