#include <iostream>
#include <fstream>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int G[100][100],n,m,x,y,i,sel[100],count=0;

int df(int nod)
{
    sel[nod]=1;
    for(i=0;i<n;i++)
        if(sel[i]==0 && G[nod][i])
          df(i);
}


int main()
{
    in>>n>>m;
    for(i=0;i<m;i++)
    {
        in>>x>>y;
        G[x][y]=G[y][x]=1;
    }
    for(i=0;i<n;i++)
    {
        if(sel[i]==0)
        {
            count++;
            df(i);
        }
    }
    out<<count;
    return 0;
}