#include <bits/stdc++.h>

using namespace std;

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

const int MAXN = 100005;
int freq[MAXN];
vector <int> v[MAXN];
int n, edge, sol, x, y;

void dfs(int nod){
    freq[nod] = 1;
    for(int i=0; i<v[nod].size(); i++)
        if(freq[v[nod][i]] == 0)
            dfs(v[nod][i]);
}

int main (){
    fin>>n>>edge;
    while(edge--){
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(int i=1; i<=n; i++)
        if(freq[i] == 0){
            sol++;
            dfs(i);
        }

    fout<<sol;
    return 0;
}