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

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m;
vector <int> v[100005];
bool viz[100005];//vizitat
void citire(){
f>>n>>m;
int x ,y;
int i;
for(i=1;i<=m;i++)
{
    f>>x>>y;
    v[x].push_back(y);
    v[y].push_back(x);
}
}
// x-nodul vizitat
void dfs(int x)
{
    viz[x]=true;
    for(unsigned int i=0;i<v[x].size();i++){
        if(!viz[v[x][i]])dfs(v[x][i]);
    }

}

int main()
{int nr=0;
    citire();
    for(int i=1;i<=n;i++){

        if(!viz[i]){
                nr++;
        dfs(i);}
    }

g<<nr;
}