#include <bits/stdc++.h>
using namespace std;
int n, m;
const int N = 1e6, M = 1e6;
pair<int, int> adj[M + 7];
long long val[N + 7];
long long sum[N + 7];
long long res = 0;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
void addRes(int numb) { res += 1LL * numb * (numb - 1) / 2; }
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  for (int i = 1, r1, r2; i <= m; i++) {
    cin >> r1 >> r2;
    adj[i] = {r1, r2};
  }
  for (int i = 1; i <= n; i++) {
    val[i] = rng();
    sum[i] = 0;
  }
  for (int i = 1; i <= m; i++) {
    sum[adj[i].first] += val[adj[i].second];
    sum[adj[i].second] += val[adj[i].first];
  }
  int u, v;
  for (int i = 1; i <= m; i++) {
    u = adj[i].first;
    v = adj[i].second;
    if (sum[u] - val[v] == sum[v] - val[u]) res++;
  }
  int start = 1, finish = 1;
  sort(sum + 1, sum + n + 1);
  for (int i = 2; i <= n; i++)
    if (sum[i] == sum[i - 1]) {
      finish = i;
      if (i == n) addRes(finish - start + 1);
    } else {
      addRes(finish - start + 1);
      start = finish = i;
    }
  cout << res;
  return 0;
}
