#include <fstream>

using namespace std;

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

const int N = 100001;
const int M = 200001;

bool viz[N];
int n,m,vf[2*M], urm[2*M], lst[N], nr=0;

void adauga(int x, int y)
{
    vf[++nr]=y;
    urm[nr]=lst[x];
    lst[x]=nr;
}

void dfs(int x)
{
    viz[x]=true;
    for(int p = lst[x]; p!=0; p=urm[p])
    {
        int y=vf[p];
        if(!viz[y])
        {
            dfs(y);
        }
    }
}

int main()
{   int x,y;
    in>>n>>m;
    for(int i=0; i<m;i++)
    {
        in>>x>>y;
        adauga(x,y);
        adauga(y,x);
    }
    int nrc=0;
    for (int i = 1; i <= n; i++)
    {
        if (!viz[i])
        {
            nrc++;
            dfs(i);
        }
    }
    out << nrc;
    out.close();
    in.close();
    return 0;
}