#include <bits/stdc++.h>
#define MAXN 100000

using namespace std;

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

char verif[MAXN + 1];
vector <int> graf[MAXN + 1];

void dfs(int nod){
    int i;

    verif[nod] = 1;

    for(i = 0; i < graf[nod].size(); i++){
        if(!verif[graf[nod][i]]){
            dfs(graf[nod][i]);
        }
    }
}

int main()
{
    int n, m, i, x, y, cnt;

    fin >> n >> m;

    for(i = 1; i <= m; i++){
        fin >> x >> y;

        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    cnt = 0;
    for(i = 1; i <= n; i++){
        if(!verif[i]){
            dfs(i);
            cnt++;
        }
    }

    fout << cnt << "\n";
    return 0;
}