#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

#define NMAX 100005

int n, m, x, y, viz[NMAX], comp_conexe;
vector<int> ad[NMAX];

void dfs(int start)
{
    queue<int> q;
    q.push(start);
    while(!q.empty()){
        int nod=q.front();
        q.pop();
        if(!viz[nod]){
            viz[nod]=1;
            for(auto &vecin: ad[nod])
                q.push(vecin);
        }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        ad[x].push_back(y);
        ad[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            comp_conexe++;
            dfs(i);
        }
    }
    fout<<comp_conexe;
    return 0;
}