#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define MAX 100020

using namespace std;

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

vector < int > v[MAX];

queue < int > q;

int n, m, nrc, viz[MAX];

void read()
    {
        int x, y;
        f>>n>>m;
        for(int i=1; i<=m; i++)
        {
            f>>x>>y;
            v[x].push_back(y);
            v[y].push_back(x);
        }
    }

void bfs(int x)
    {
        q.push(x);
        while(!q.empty())
        {
            int nod = q.front();
            q.pop();
            if(viz[nod]==0)
            {
                viz[nod]=nrc;
                for(auto it : v[nod])
                    if(viz[it]==0)
                        q.push(it);
            }
        }
    }

int main()
{
    read();
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            nrc++;
            bfs(i);
        }
    }
    g<<nrc;
}