#include <fstream>
#include <vector>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int NMax = 100005;

int N, M;
vector < int > edge[NMax];

bool viz[NMax];
int conexe;

void DFS(int node)
{
    int i;
    viz[node]=1;
    for(i=0; i< edge[node].size(); i++ )
    {
        int next = edge[node][i];
        if(viz[next]==0)
            DFS(next);
    }
}

void Read()
{
    int i;
    fin>>N>>M;
    for(i=0; i<M; i++)
    {
        int x,y;
        fin>>x>>y;
        edge[x].push_back(y);
        edge[y].push_back(x);

    }
    for(i=0; i<N; i++)
        if(viz[i]==0)
        {
            conexe++;
            DFS(i);
        }
    fout<<conexe;
}

int main()
{
    Read();
    return 0;
}