#include <iostream>
#include <fstream>
using namespace std;

int V[10000][10000],viz[10000],n,k;

void dfs(unsigned nod)
{
    viz[nod]=1;
    for(unsigned i=1;i<=n;i++)
        if(viz[i]==0&&V[nod][i]==1)
            dfs(i);
}


int main()
{
    ifstream f("dfs.in");
    f>>n;
    unsigned x,y;
    f>>x;
    while(f>>x>>y)
    {
        V[x][y]=1;
        V[y][x]=1;
    }
    f.close();
    for(unsigned i=1;i<=n;i++)
        if(viz[i]==0)
        {
            k++;
            dfs(i);
        }
    ofstream g("dfs.out");
    g<<k;
    g.close();
    return 0;
}