#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
const int N=100001;
vector <int> v[N];
int n,m;
bool viz[N];
void citire()
{
    f>>n>>m;
    for(int i=1;i<=m;i++){
        int x,y;
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    f.close();
}
void dfs(int x)
{
    viz[x]=true;
    int y;
    for(int i=0;i<v[x].size();i++){
        y=v[x][i];
        if(!viz[y])
            dfs(y);
    }
}
int main()
{
    citire();
    int r=0;
    for(int i=1;i<=n;i++)
    if(!viz[i]){
        r++;
        dfs(i);
    }
    g<<r;
    return 0;
}