#include<cstdio>
#include<vector>

using namespace std;

#define MAX_N   100010

vector<int> L[MAX_N];

int c[MAX_N+MAX_N];
bool v[MAX_N];

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

int n, m, conexeCount;

void file_in() {
    int x, y;
    if (freopen("dfs.in", "rt", stdin));
    if (scanf("%d %d", &n, &m));
    for (int i=1; i<=n; ++i) {
        if (scanf("%d %d", &x, &y));
        L[x].push_back(y);
        L[y].push_back(x);
    }
    fclose(stdin);
}


void file_out() {
    if (freopen("dfs.out", "wt", stdout));
    printf ("%d ", conexeCount);
    fclose(stdout);
}

int main() {
    file_in();

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



    file_out();
    return 0;
}