#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
///vector< int > v[101];
///bool vizitat[101];
/*
void dfs(int nod){
vizitat[nod] = true;
cout << nod << " ";
for(int i = 0; i < v[nod].size(); ++i)
if(!(vizitat[v[nod][i]]))
dfs(v[nod][i]);
}
void bfs(int nod){
queue< int > q;
q.push(nod);
while(!(q.empty()))
{
int crt = q.front();
cout << crt << " ";
for(int i = 0; i < v[crt].size(); ++i)
if(!(vizitat[v[crt][i]]))
{
q.push(v[crt][i]);
vizitat[v[crt][i]] = true;
}
}
}
*/
class Graph{
public:
bool vis[200001];
int noduri, muchii;
vector<vector<int>> adj;
Graph(int _noduri, int _muchii): noduri(_noduri), muchii(_muchii){
for(int i = 0; i < _noduri + 1; ++i)
{ vector <int> temp;
adj.push_back(temp);
}
}
int get_size(){
return adj.size();
}
int gett(){
cout << noduri << muchii;
}
void build(){
for(int i = 0; i < muchii; ++i)
{
int x, y;
in >> x >> y;
adj[x].push_back(y);
adj[y].push_back(x);
}
}
int print(){
for(int i = 1; i < noduri + 1; ++i)
{ cout << i << ": ";
for(int j = 0; j < adj[i].size(); ++j)
cout << adj[i][j] << " ";
cout << "\n";
}
}
int dfs(int nod){
//cout << nod << " ";
vis[nod] = true;
for(int i = 0; i < adj[nod].size(); ++i)
if(!(vis[adj[nod][i]]))
dfs(adj[nod][i]);
}
int getCconexe(){
int cnt = 0;
for(int i = 1; i <= noduri; ++i)
if(!(vis[i]))
{
++cnt;
dfs(i);
}
return cnt;
}
};
int main()
{ int N, M;
in >> N >> M;
Graph g(N, M);
g.build();
out << g.getCconexe();
return 0;
}