#include <bits/stdc++.h >

using namespace std;

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

int n, m, x, y, v[100010], c;
vector <int> e[100010];

void dfs(int nod)
{
    v[nod] = 1;
    for(auto vecin : e[nod]){
        if(v[vecin] == 0)
            dfs(vecin);
    }
}

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