#include <iostream>
#include <vector>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <fstream>
#include <cctype>
#include <iomanip>
#include <cmath>
#include <cstring>
#include <map>
#include <bitset>
#include <stack>
/*  //c++11
#include <unordered_map>
#include <unordered_set>
#include <tuple>
*/

using namespace std;

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

vector<int> V[100001];
bitset<100001> used;

void dfs(int node)
{
    used[node] = true;
    for(vector<int>::iterator it = V[node].begin(); it != V[node].end(); it++)
        if(!used[*it])
            dfs(*it);
}

int main()
{
    //freopen("1.in","r",stdin);
    //freopen("1.out","w",stdout);
    int n,m,x,y;
    fin>>n>>m;
    for(int i =1;i<=m;i++)
    {
        fin>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);


    }
    int res = 0;
    for(int i = 1; i <= n; i++)
        if(!used[i])
        {
            dfs(i);
            res++;
        }
    fout<<res;
    return 0;
}


//FILE!!!