#include <fstream>
#include <vector>
#define NMAX 100000

using namespace std;
ifstream fin ("vector.in");
ofstream fout ("vector.out");

int n,m,uz[NMAX],nrc;
vector<int> G[NMAX];
void citire();
void DFS(int k);
int main()
{int i;
    citire();
    for(i=1;i<=n;i++)
        if(!uz[i])
    {
        nrc++;
        DFS(i);
    }
    fout<<nrc;
    return 0;
}

void citire()
{
    int i, x, y;
    fin >>n>>m;
    for (i = 0; i < m; i++)
    {//arc
        fin >>x>>y;
        G[x].push_back (y);
        G[y].push_back (x);
    }
}

void DFS(int k)
{int i;
    uz[k] = 1;
    for (i=0; i<G[k].size(); i++)
        if (uz[G[k][i]] == 0)
        DFS (G[k][i]);
}