#include <bits/stdc++.h>
using namespace std;
stringstream ss;
long long p[1000010], h1[1000010], h2[1000010];
int main() {
  p[0] = 1;
  for (int i = 1; i < 1000010; i++) h1[i] = p[i] = p[i - 1] * 127LL;
  int n, m, a, b;
  cin >> n >> m;
  for (int i = 1; i <= m; i++) {
    cin >> a >> b;
    h1[a] += p[b];
    h2[a] += p[b];
    h1[b] += p[a];
    h2[b] += p[a];
  }
  sort(h1 + 1, h1 + 1 + n);
  sort(h2 + 1, h2 + 1 + n);
  long long res = 0;
  for (int i = 1; i <= n; i++) {
    long long cnt = 1;
    while (i + 1 <= n && h1[i] == h1[i + 1]) cnt++, i++;
    res += (cnt) * (cnt - 1) / 2LL;
  }
  for (int i = 1; i <= n; i++) {
    long long cnt = 1;
    while (i + 1 <= n && h2[i] == h2[i + 1]) cnt++, i++;
    res += (cnt) * (cnt - 1) / 2LL;
  }
  cout << res << endl;
  return 0;
}
