#line 1 "main.cpp"

/**
 * @title Template
 */

#include <iostream>
#include <algorithm>
#include <utility>
#include <numeric>
#include <vector>
#include <array>
#include <cassert>
#include <stack>

#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/chmin_chmax.cpp"

template <class T, class U>
constexpr bool chmin(T &lhs, const U &rhs) {
  if (lhs > rhs) { lhs = rhs; return true; }
  return false;
}

template <class T, class U>
constexpr bool chmax(T &lhs, const U &rhs) {
  if (lhs < rhs) { lhs = rhs; return true; }
  return false;
}

/**
 * @title Chmin/Chmax
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

#line 4 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

class range {
public:
  class iterator {
  private:
    int64_t M_position;

  public:
    constexpr iterator(int64_t position) noexcept: M_position(position) { }
    constexpr void operator ++ () noexcept { ++M_position; }
    constexpr bool operator != (iterator other) const noexcept { return M_position != other.M_position; }
    constexpr int64_t operator * () const noexcept { return M_position; }

  };

  class reverse_iterator {
  private:
    int64_t M_position;
  
  public:
    constexpr reverse_iterator(int64_t position) noexcept: M_position(position) { }
    constexpr void operator ++ () noexcept { --M_position; }
    constexpr bool operator != (reverse_iterator other) const noexcept { return M_position != other.M_position; }
    constexpr int64_t operator * () const noexcept { return M_position; }

  };
  
private:
  const iterator M_first, M_last;

public:
  constexpr range(int64_t first, int64_t last) noexcept: M_first(first), M_last(std::max(first, last)) { }
  constexpr iterator begin() const noexcept { return M_first; }
  constexpr iterator end() const noexcept { return M_last; }
  constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator(*M_last - 1); } 
  constexpr reverse_iterator rend() const noexcept { return reverse_iterator(*M_first - 1); } 

};

/**
 * @title Range
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

#include <type_traits>
#include <iterator>
#line 6 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

template <class T>
class rev_impl {
public:
  using iterator = decltype(std::rbegin(std::declval<T>()));

private:
  const iterator M_begin;
  const iterator M_end;

public:
  constexpr rev_impl(T &&cont) noexcept: M_begin(std::rbegin(cont)), M_end(std::rend(cont)) { }
  constexpr iterator begin() const noexcept { return M_begin; }
  constexpr iterator end() const noexcept { return M_end; }

};

template <class T>
constexpr decltype(auto) rev(T &&cont) {
  return rev_impl<T>(std::forward<T>(cont));
}

/**
 * @title Reverser
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/fix_point.cpp"

#line 4 "/Users/kodamankod/Desktop/Programming/Library/other/fix_point.cpp"

template <class Func>
struct fix_point_impl: private Func {
  explicit constexpr fix_point_impl(Func &&func): Func(std::forward<Func>(func)) { }
  template <class... Args>
  constexpr decltype(auto) operator () (Args &&... args) const {
    return Func::operator()(*this, std::forward<Args>(args)...);
  }
};

template <class Func>
constexpr decltype(auto) fix_point(Func &&func) {
  return fix_point_impl<Func>(std::forward<Func>(func));
}

/**
 * @title Lambda Recursion
 */
#line 19 "main.cpp"

using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;

constexpr i32 inf32 = (i32(1) << 30) - 1;
constexpr i64 inf64 = (i64(1) << 62) - 1;

int main() {
  i32 N, M;
  std::cin >> N >> M;
  std::vector<i32> nums;
  nums.reserve(2 * M);
  std::vector<i32> U(M), V(M);
  for (auto i: range(0, M)) {
    std::cin >> U[i] >> V[i];
    nums.push_back(U[i]);
    nums.push_back(V[i]);
  }
  std::sort(nums.begin(), nums.end());
  nums.erase(std::unique(nums.begin(), nums.end()), nums.end());
  i64 ans = (i64) N * (N + 1) / 2;
  for (auto x: nums) {
    ans -= x;
  }
  N = nums.size();
  std::vector<std::vector<i32>> graph(N), revgraph(N);
  for (auto i: range(0, M)) {
    U[i] = std::lower_bound(nums.begin(), nums.end(), U[i]) - nums.begin();
    V[i] = std::lower_bound(nums.begin(), nums.end(), V[i]) - nums.begin();
    graph[U[i]].push_back(V[i]);
    revgraph[V[i]].push_back(U[i]);
  }
  std::vector<bool> visited(N);
  std::stack<i32> stack;
  const auto tag = fix_point([&](auto dfs, const i32 u) -> void {
    if (visited[u]) {
      return;
    }
    visited[u] = true;
    for (auto v: graph[u]) {
      dfs(v);
    }
    stack.push(u);
  });
  for (auto i: range(0, N)) {
    tag(i);
  }
  std::fill(visited.begin(), visited.end(), false);
  std::vector<std::vector<i32>> group;
  const auto dec = fix_point([&](auto dfs, const i32 u) -> void {
    if (visited[u]) {
      return;
    }
    visited[u] = true;
    group.back().push_back(u);
    for (auto v: revgraph[u]) {
      dfs(v);
    }
  });
  while (!stack.empty()) {
    const auto u = stack.top();
    stack.pop();
    if (!visited[u]) {
      group.push_back({ });
      dec(u);
    }
  }
  const i32 G = group.size();
  std::vector<std::vector<i32>> newgraph(G);
  std::vector<i32> belong(N);
  for (auto i: range(0, G)) {
    for (auto x: group[i]) {
      belong[x] = i;
    }
  }
  for (auto i: range(0, N)) {
    for (auto v: graph[i]) {
      newgraph[belong[i]].push_back(belong[v]);
    }
  }
  std::vector<i32> max(G);
  for (auto i: rev(range(0, G))) {
    for (auto x: group[i]) {
      chmax(max[i], nums[x]);
    }
    for (auto j: newgraph[i]) {
      chmax(max[i], max[j]);
    }
    ans += (i64) max[i] * group[i].size();
  }
  std::cout << ans << '\n';
  return 0;
}