#include <iostream>
#include <fstream>
#include <stack>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
stack < int > stiva;
vector < int > v[100002];
bool viz[100002];
int n,m,i,j,nc;
void dfs (int x)
{
    stiva.push(x);
    viz[x]=1;
    int l=v[x].size();
    for(int k=0; k<l; k++)
        if(!viz[v[x].at(k)])
        {
            viz[v[x].at(k)]=1;
            dfs(v[x].at(k));
        }
}
int main()
{
    f>>n>>m;
    for(;m;m--)
    {
        f>>i>>j;
        v[i].push_back(j);
        v[j].push_back(i);
    }
    for(i=1; i<=n; i++)
        if(!viz[i])
        {
              nc++;
            dfs(i);
        }
    g<<nc;
    return 0;
}