#include <iostream>
#include <fstream>
using namespace std;
int a[100][100],n,m,viz[100]={0};

void citire()
{
    ifstream f("dfs.in");
    f>>n>>m;

    int k,x,y;
    for(k=1;k<=n;k++)
    {
        f>>x>>y;
        a[x][y]=a[y][x]=1;
    }


}

void DFS(int v)
{
    int i;
    viz[v]=1;
    for(i=1;i<=n;i++)
        if(a[v][i]&&!viz[i])
    {
        DFS(i);
    }


}



int main()
{
    int c=0;
    citire();
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            DFS(i);
            c++;
        }
ofstream g("dfs.out");
g<<c;
    return 0;
}