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

long viz[100000];
std::vector<long> v[100000];

void dfs(long i)
{
    viz[i]=1;
    long lim;
    lim=v[i].size();
    int j;
    for(j=0;j<lim;j++)
    {
        if(viz[v[i][j]]==0)
        dfs(v[i][j]);
    }


}

int main()
{
    long n,m,x,y,i,compconex=0;
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f>>n>>m;
   for(i=1;i<=m;i++)
    {
        f>>x>>y;
         v[x].push_back(y);
         v[y].push_back(x);
    }

    for(i=1;i<=n;i++)
    {
        if(viz[i]==0) {
            dfs(i);
            compconex++;
        }
    }
    g<<compconex;
    return 0;
}