/*
ID: gabriel100
LANG: C++
TASK:
*/
#include <cstdio>
#include <algorithm>
//#include <time.h>
#include <queue>
#include <cmath>
#include <stack>
#include <fstream>
#include <bitset>
#include <set>
#include <map>
#include <ctime>

#define nl '\n'
#define F first
#define S second
#define vi vector<int>
#define all(v) v.begin(),v.end()
#define eb(x) emplace_back(x)
#define ull unsigned long long
#define ll long long
#define ProblemName "dfs"
#define LocalName "data"
#ifdef INFOARENA
#define Filename ProblemName
#else
#define Filename LocalName
#endif
#define Input Filename".in"
#define Output Filename".out"
using namespace std;
ifstream cin(Input);
ofstream cout(Output);

template<class a, class type>
void print(a v, type t) {
    for_each(all(v), [](type x) { cout << x << ' '; });
    cout << nl;
}

typedef struct nod {
    int val;
    nod *list;
}*p;
int n, m,x,y;
p v[100001];
inline void add(p &next, int val){
    p newNod = new nod;
    newNod -> val = val;
    newNod -> list = next;
    next = newNod;
}
bitset<100001> viz;
inline void dfs(int i){
    p newNod;
    viz[i] = 1;
    for(newNod = v[i];newNod!=NULL; newNod = newNod->list){
        if(!viz[newNod->val]){
            dfs(newNod->val);
        }
    }
}
int main() {
    ios_base::sync_with_stdio(false);
    clock_t tStart = clock();
    cin >> n >> m;
    for(int i=0;i<m;++i) {
        cin >> x >> y;
        add(v[x],y);
        add(v[y],x);
    }
    int ans = 0;
    for(int i=1;i<=n;++i){
        if(!viz[i]){
            ++ans;
            dfs(i);
        }
    }
    cout << ans << nl;
    cout.close();
    printf("\nTime taken: %.2fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
}