#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

const int N=100001;
vector <int> a[N];
int n,m,X;
bool viz[N];
void read()
{
    ifstream fin("dfs.in");

    int x,y;
    fin>>n>>m;
    while(fin>>x>>y)
    {
        //fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    fin.close();
}

void dfs(int x)
{
    ofstream fout("dfs.out");
    //fout<<x<<' ';
    viz[x]=true;
    for(auto y:a[x])
    {
        if(!viz[y])
        {
            dfs(y);
        }
    }
    //step[++nr]=x;
}
int main()
{
    int nc;
    read();
    nc=0;
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            nc++;
            dfs(i);
        }
    }
    cout<<nc;
    return 0;
}