#include<fstream>
#include<vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int N=100000;
bool viz[N];
int n,m;
vector<int> a[N];
void citire();
void dfs(int x0);
int main(){

    int nr=0,i;
    citire();
    for( i=1;i<=n;i++)
        if(viz[i]==false)
        {
            dfs(i);
            nr++;
        }

    out<<nr<<"\n";
    return 0;
}

void citire()
{
    int i,x,y;
    in>>n>>m;
    for(i=1;i<=m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);

    }
}
void dfs(int x0){
    viz[x0]=true;
    int y;
    for(int i=0;i<a[x0].size();i++)
    {
        y=a[x0][i];
        if(!viz[y])
            dfs(y);
    }
}