#include <fstream>
#include <vector>

using namespace std;

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

vector <int> G[100005];
int n, m, i, a, b, intr;
bool v[100005];

void dfs(int nod){
    v[nod] = 1;
    vector <int>::iterator it;
    for (it = G[nod].begin(); it != G[nod].end(); it ++)
        if (v[*it] == 0)
            dfs(*it);
}

int main()
{
    fin >> n >> m;
    for (i = 1; i <= m; i ++){
        fin >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    for (i = 1; i <= n; i ++){
        if (v[i] == 0){
            intr ++;
            dfs(i);
        }
    }
    fout << intr;
    return 0;
}