//#include <iostream>
#include <bits/stdc++.h>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int Max=100005;
vector <int >v[Max];
int n,m; bool viz[Max];
void citire()
{
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y; in>>x>>y;
        v[x].push_back(y); v[y].push_back(x);
    }

}
void dfs(int nod)
{
    viz[nod]=1;
    for(int j=0;j<v[nod].size();j++)
    {
        int vecin=v[nod][j];
        if(!viz[vecin])
            dfs(vecin);
    }
}
int main()
{
    citire();
    int nrc=0;
    for(int i=1;i<=n;i++)
        if(!viz[i])
    {
        nrc++;
        dfs(i);
    }
    out<<nrc;
    return 0;
}