#include <iostream>
#include <fstream>
#include <vector>
#define DIM 100005

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

struct node{
    int info;
    node *next;
}*L[DIM];

int n,m;
bool used[DIM];

void add(int x, int y){
    node *p = new node;
    p->info = y;
    p->next = L[x];
    L[x] = p;
}

void citire(int &n, int &m){
    f>>n>>m;
    int x,y;
    for(int i=1; i<=m; i++){
        f>>x>>y;
        add(x,y);
        add(y,x);
    }
}

void DFS(int nod){
    used[nod] = 1;
    for(node *p = L[nod]; p != NULL; p = p->next)
        if(used[p->info] == 0)
            DFS(p->info);
}

int main() {
   citire(n,m);
   int s=0;
   for(int i=1; i<=n; i++)
        if(used[i] == 0){
            s++;
            DFS(i);
        }
    g<<s;
}