#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
const long long mod = 1000000007;
void solve() {
  int n, m, u, v;
  cin >> n >> m;
  vector<int> adj[n + 1];
  for (int i = 0; i < m; i++) {
    cin >> u >> v;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  vector<pair<long long, long long> > hash, hash_orig;
  hash.reserve(n);
  long long p1 = 31, p2 = 53, h1, h2;
  long long pow_p1[n + 1], pow_p2[n + 1];
  pow_p1[0] = pow_p2[0] = 1;
  for (int i = 1; i <= n; i++) {
    pow_p1[i] = pow_p1[i - 1] * p1 % mod;
    pow_p2[i] = pow_p2[i - 1] * p2 % mod;
  }
  for (int i = 1; i <= n; i++) {
    h1 = 0;
    h2 = 0;
    for (int &j : adj[i]) {
      h1 += pow_p1[j];
      h2 += pow_p2[j];
    }
    hash.push_back({h1, h2});
  }
  hash_orig = hash;
  sort((hash).begin(), (hash).end());
  long long ans = 0;
  int cnt = 1;
  for (int i = 1; i < n; i++) {
    if (hash[i] != hash[i - 1]) {
      ans += 1ll * cnt * (cnt - 1) / 2;
      cnt = 1;
    } else
      cnt++;
  }
  ans += 1ll * cnt * (cnt - 1) / 2;
  for (int i = 1; i <= n; i++) {
    hash_orig[i - 1].first += pow_p1[i];
    hash_orig[i - 1].second += pow_p2[i];
  }
  for (int i = 1; i <= n; i++) {
    for (int &j : adj[i]) {
      if (j < i || adj[i].size() != adj[j].size()) continue;
      if (hash_orig[i - 1] == hash_orig[j - 1]) ans++;
    }
  }
  cout << ans << "\n";
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int t = 1;
  while (t--) {
    solve();
  }
}
