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

using namespace std;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

vector <int> gr[100005];
int v[100005];
int n,m,nr;

void read()
{
    fin >> n >> m;
    for(int i=0;i<m;++i)
    {
        int x,y;
        fin >> x >> y;
        gr[x].push_back(y);
        gr[y].push_back(x);
    }
}

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

int main()
{
    read();
    for(int i=1;i<=n;++i)
    {
        if(v[i]==0)
        {
            nr++;
            dfs(i);
        }
    }
    fout << nr;
    return 0;
}