#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int N=100001;
vector<int>H[N];
bool uz[N];
void dfs(int nod)
{
    uz[nod]=1;
    for(vector<int>::iterator it=H[nod].begin();it!=H[nod].end();it++)
    {
        if(uz[*it]==0) dfs(*it);
    }
}
int main()
{
    int n,m,a,b,i,tot=0;
    fin>>n>>m;
    while(m--)
    {
        fin>>a>>b;
        H[a].push_back(b);
        H[b].push_back(a);
    }
    for(i=1;i<=n;i++)
    {
        if(uz[i]==0)
        {
            tot++;
            dfs(i);
        }
    }
    fout<<tot;
}