#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using i128 = __int128;
using u128 = unsigned __int128;
template <typename T>
void chkmax(T &x, const T &y) {
  x = max(x, y);
}
template <typename T>
void chkmin(T &x, const T &y) {
  x = min(x, y);
}
constexpr int MAXN = 2.5e5 + 10;
int n, m, deg[MAXN], cnt[MAXN], lim[MAXN];
pair<int, int> edg[MAXN];
vector<int> tol[MAXN], tor[MAXN];
namespace dsu {
int fa[MAXN], sz[MAXN], tp, stk[MAXN];
void init() {
  for (int i = 1; i <= n; ++i) {
    fa[i] = i;
    sz[i] = 1;
  }
}
int find(int x) {
  while (x != fa[x]) x = fa[x];
  return x;
}
bool merge(int u, int v) {
  u = find(u);
  v = find(v);
  if (u == v) return false;
  if (sz[u] > sz[v]) swap(u, v);
  fa[u] = v;
  sz[v] += sz[u];
  stk[++tp] = u;
  return true;
}
void undo() {
  int u = stk[tp--], v = fa[u];
  sz[v] -= sz[u];
  fa[u] = u;
}
}  // namespace dsu
namespace sgt1 {
int ptr;
vector<pair<int, int>> buc[MAXN * 4];
int ls(int p) { return p << 1; }
int rs(int p) { return p << 1 | 1; }
void insert(int p, int l, int r, int ql, int qr, const pair<int, int> &x) {
  if (ql <= l && r <= qr) {
    buc[p].emplace_back(x);
    return;
  }
  int mid = (l + r) >> 1;
  if (ql <= mid) insert(ls(p), l, mid, ql, qr, x);
  if (qr > mid) insert(rs(p), mid + 1, r, ql, qr, x);
}
void solve(int p, int l, int r) {
  int tmp = dsu::tp;
  for (auto &i : buc[p]) dsu::merge(i.first, i.second);
  if (l == r) {
    int pre = ptr;
    while (ptr && (edg[ptr].second > l || dsu::merge(edg[ptr].first, edg[ptr].second)))
      --ptr;
    chkmax(lim[l], edg[ptr].first + 1);
    for (int i = ptr + 1; i <= pre; ++i)
      if (edg[i].second < l) insert(1, 1, n, edg[i].second, l - 1, edg[i]);
  } else {
    int mid = (l + r) >> 1;
    solve(rs(p), mid + 1, r);
    solve(ls(p), l, mid);
  }
  while (dsu::tp > tmp) dsu::undo();
}
}  // namespace sgt1
namespace sgt2 {
int ls(int p) { return p << 1; }
int rs(int p) { return p << 1 | 1; }
struct node {
  int mx, cnt;
};
node operator+(const node &x, const node &y) {
  if (x.mx > y.mx) return x;
  if (x.mx < y.mx) return y;
  return {x.mx, x.cnt + y.cnt};
}
int tag[MAXN * 4];
node tr[MAXN * 4];
void push_up(int p) { tr[p] = tr[ls(p)] + tr[rs(p)]; }
void get_down(int p, int x) {
  tr[p].mx += x;
  tag[p] += x;
}
void push_down(int p) {
  if (tag[p]) {
    get_down(ls(p), tag[p]);
    get_down(rs(p), tag[p]);
    tag[p] = 0;
  }
}
void build(int p, int l, int r) {
  if (l == r) {
    tr[p] = {l, 1};
    return;
  }
  int mid = (l + r) >> 1;
  build(ls(p), l, mid);
  build(rs(p), mid + 1, r);
  push_up(p);
}
void update(int p, int l, int r, int ql, int qr, int x) {
  if (ql <= l && r <= qr) {
    get_down(p, x);
    return;
  }
  push_down(p);
  int mid = (l + r) >> 1;
  if (ql <= mid) update(ls(p), l, mid, ql, qr, x);
  if (qr > mid) update(rs(p), mid + 1, r, ql, qr, x);
  push_up(p);
}
node query(int p, int l, int r, int ql, int qr) {
  if (ql <= l && r <= qr) return tr[p];
  push_down(p);
  int mid = (l + r) >> 1;
  if (qr <= mid) return query(ls(p), l, mid, ql, qr);
  if (ql > mid) return query(rs(p), mid + 1, r, ql, qr);
  return query(ls(p), l, mid, ql, qr) + query(rs(p), mid + 1, r, ql, qr);
}
}  // namespace sgt2
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cin >> n >> m;
  for (int i = 1, u, v; i <= m; ++i) {
    cin >> u >> v;
    if (u > v) swap(u, v);
    tor[u].emplace_back(v);
    tol[v].emplace_back(u);
    edg[i] = {u, v};
  }
  cnt[0] = n;
  for (int i = 1, j = 1, maxi = 0; i <= n; ++i) {
    for (auto x : tol[i]) {
      if (x >= j) {
        --cnt[deg[x]];
        ++cnt[++deg[x]];
        chkmax(maxi, deg[x]);
        ++deg[i];
      }
    }
    ++cnt[deg[i]];
    chkmax(maxi, deg[i]);
    for (; maxi > 2; ++j) {
      for (auto x : tor[j]) {
        if (x <= i) {
          --cnt[deg[x]];
          ++cnt[--deg[x]];
        }
      }
      --cnt[deg[j]];
      ++cnt[0];
      deg[j] = 0;
      while (!cnt[maxi]) --maxi;
    }
    lim[i] = j;
  }
  sort(edg + 1, edg + m + 1);
  dsu::init();
  sgt1::ptr = m;
  sgt1::solve(1, 1, n);
  sgt2::build(1, 1, n);
  ll ans = 0;
  for (int i = 1; i <= n; ++i) {
    for (auto j : tol[i]) sgt2::update(1, 1, n, 1, j, 1);
    auto tmp = sgt2::query(1, 1, n, lim[i], i);
    ans += tmp.cnt;
  }
  cout << ans << "\n";
  return 0;
}
/*
g++ chemistry.cpp -o chemistry -std=c++14 -O2 -Wall -Wextra -Wshadow -g -fsanitize=address,undefined
*/
/*
3 3
1 2
2 3
3 1
*/