#include <fstream>
#include <bits/stdc++.h>
using namespace std;
vector <int>l[100005];
bool viz[100005];
int n,m;
ifstream in("dfs.in");
ofstream out("dfs.out");

void citire()
{
    in>>n>>m;
    int x,y,i;
    for(int i =0; i<m; i++)
    {
        in>>x>>y;
        l[x].push_back(y);
        l[y].push_back(x);
    }
}

void dfs(int s)
{
    viz[s]=1;
    for(auto el:l[s])
    {
        if(viz[el]==0)
        {
            dfs(el);
        }
    }
}

int main()
{
    citire();
    int c_con=0;
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            c_con++;
        }
    }
    out<<c_con;
    return 0;
}