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

using namespace std;
ifstream fin ("dfs.in");
ofstream fout("dfs.out");
vector <int> v[100005];
int noduri[100005];
void dfs(int k)
{
    int i;
    noduri[k]=1;
    for(i=0;i<v[k].size();i++)
    {
        if(noduri[v[k][i]]==0)
            dfs(v[k][i]);
    }
}

int main()
{

    int nr=0, i, n, m, x, y;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(noduri[i]==0)
        {
            nr=nr+1;
            dfs(i);
        }
    }
    fout<<nr<<"\n";
    return 0;
}