#include <iostream>
#include <cstdio>
#include <vector>
#include <bitset>

using namespace std;

const int NodMax = 100005;
const int MuchMax = 200005;

int N, M;
bitset < NodMax > viz;
vector < int > G[MuchMax];

void Read()
{
    scanf("%d %d", &N, &M);
    for(int i=1; i<=M; ++i)
    {
        int x, y;
        scanf("%d %d", &x, &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS(int nod)
{
    viz[nod] = true;

    vector < int > ::iterator it;

    for(it=G[nod].begin(); it!=G[nod].end(); ++it)
    {
        if(!viz[*it])
        {
            DFS(*it);
        }
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

   Read();

   int Comp_Conexe = 0;

   for(int i=1; i<=N; ++i)
   {
       if(!viz[i])
       {
           DFS(i);
           ++Comp_Conexe;
       }
   }

   printf("%d", Comp_Conexe);

    return 0;
}