#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
const int nlim=100005;
bool v[nlim];
vector <int> a[nlim];
int n,m,x,y,nr;

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

    }
}
void dfs(int p){
v[p]=true;
for(unsigned int j=0;j<a[p].size();j++ ){
    int vecin= a[p][j];
    if(!v[vecin]){
      dfs(vecin);
    }
}
}
int main()
{
citire();
for(int i=1;i<=n;i++){
 if(!v[i]){
 nr++;
 dfs(i);
 }
}
g<<nr;
}