#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <set>
#include <map>

using namespace std;

const long long MOD = 1442501923, MOD2 = 2556975823;
const long long p = 1337057, p2 = 1216091;

int main() {
    int n, m;
    cin >> n >> m;
    vector<vector<int>> g(n + 1), gg(n + 1);
    for (int i = 0; i < m; ++i) {
        int v, u;
        cin >> v >> u;
        g[v].push_back(u);
        gg[v].push_back(u);
        g[u].push_back(v);
        gg[u].push_back(v);
    }
    for (int i = 1; i <= n; ++i) {
        gg[i].push_back(i);
        sort(g[i].begin(), g[i].end());
        sort(gg[i].begin(), gg[i].end());
    }
    vector<long long> h, hh, h2, hh2;
    for (int i = 1; i <= n; ++i) {
        long long hs = 0LL, hs2 = 0LL;
        long long pow = 1LL, pow2 = 1LL;
        for (int j: g[i]) {
            hs = (hs + (long long)(j) * pow) % MOD;
            hs2 = (hs2 + (long long)(j) * pow2) % MOD2;
            pow = (pow * p) % MOD;
            pow2 = (pow2 * p2) % MOD2;
        }
        h.push_back(hs);
        h2.push_back(hs2);
        hs = 0LL;
        pow = 1LL;
        hs2 = 0LL;
        pow2 = 1LL;
        for (int j: gg[i]) {
            hs = (hs + (long long)(j) * pow) % MOD;
            hs2 = (hs2 + (long long)(j) * pow2) % MOD2;
            pow = (pow * p) % MOD;
            pow2 = (pow2 * p2) % MOD2;
        }
        hh.push_back(hs);
        hh2.push_back(hs2);
    }
    sort(h.begin(), h.end());
    sort(hh.begin(), hh.end());
    sort(h2.begin(), h2.end());
    sort(hh2.begin(), hh2.end());
    h.push_back(-1);
    hh.push_back(-1);
    h2.push_back(-1);
    hh2.push_back(-1);
    long long ans = 0LL;
    int prev = 0;
    for (int i = 1; i < n + 1; ++i) {
        if (h[i] != h[prev] || h2[i] != h2[prev]) {
            ans += (long long)(i - prev) * (long long)(i - prev - 1) / 2LL;
            prev = i;
        }
    }
    prev = 0;
    for (int i = 1; i < n + 1; ++i) {
        if (hh[i] != hh[prev] || hh2[i] != hh2[prev]) {
            ans += (long long)(i - prev) * (long long)(i - prev - 1) / 2LL;
            prev = i;
        }
    }
    cout << ans;
    return 0;
}