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

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int viz[100001];
vector <int> graph[100001];
void dfs(int node)
{
    viz[node]=1;
    int lim=graph[node].size();
    for(int i=0; i<lim; i++)
    {
        int vecin= graph[node][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}

int main()
{
int N,M;
int X,Y;
int answer=0;
fin>>N>>M;
 for(int i=1; i<=M; i++)
 {
    fin>>X>>Y;
    graph[X].push_back(Y);
    graph[Y].push_back(X);
 }
 for( int i=1; i<=N; i++)
 {
    if(!viz[i])
    {
        dfs(i);
        answer++;
    }
 }
 fout<<answer;
    return 0;
}