#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int viz[100001];
vector <int> graph[100001];
void dfs(int nod)
{
    int Size=graph[nod].size();
    viz[nod]=1;
    for(int i=0; i<Size; i++)
    {
        int vecin = graph[nod][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}
int main()
{
    int N,M,x,y,comp=0;
    fin>>N>>M;
    for(int i=0; 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])
        {
            comp++;
            dfs(i);
        }
    fout<<comp;
    return 0;
}