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

using namespace std;

const int N=100000;

int n,m;
vector<int> graph[N];
bool use[N];

void dfs(int x)
{
    use[x]=1;

    vector<int>::iterator it;
    for(it=graph[x].begin(); it!=graph[x].end(); it++)
    {
        if(!use[*it])
            dfs(*it);
    }
}

int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin>>n>>m;
    int conexe=0;
    for(int i=1; i<=m; i++)
    {
        int x,y;
        fin>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }

    for(int i=1; i<=n; i++)
    {
        if(!use[i])
         {
            conexe++;
            dfs(i);
         }
    }
    fout<<conexe;
    return 0;
}