3 3
1 2
3 1
2 3
 2 0
 10 17
1 2
1 3
1 4
1 5
1 6
1 7
1 8
1 9
1 10
2 3
3 4
4 5
5 6
6 7
7 8
8 9
9 10
 2 1
1 2
 8 13
1 2
2 3
3 4
4 1
2 4
1 3
5 6
6 7
7 8
8 5
6 8
5 7
1 8
 3 2
1 2
2 3
 10 9
1 2
1 3
1 4
1 5
1 6
1 7
1 8
1 9
1 10
 10 40
1 3
2 6
9 10
4 6
1 2
1 8
6 10
3 6
1 4
5 7
3 8
3 9
4 5
3 7
8 9
5 9
5 6
2 3
3 4
1 6
4 8
3 10
5 10
2 8
2 10
4 7
1 10
1 7
4 10
5 8
8 10
7 9
6 8
2 7
4 9
6 9
7 8
6 7
1 5
2 9
 10 9
1 2
2 3
3 1
4 5
5 6
6 7
7 4
4 6
5 7
 1000000 0
 8 11
1 2
1 3
1 4
2 3
2 7
7 4
4 2
7 5
8 1
1 7
7 8
 9 9
1 2
2 3
3 1
4 5
5 6
6 4
7 8
8 9
9 7
 15 14
1 2
1 3
1 4
1 5
2 6
2 7
7 8
7 9
3 10
10 11
4 12
12 13
13 14
13 15
 10 17
1 2
1 3
1 4
1 5
1 6
1 7
1 8
1 9
1 10
2 3
2 4
2 5
2 6
2 7
2 8
2 9
2 10
 9 12
1 2
2 3
3 1
1 4
4 5
5 1
1 6
6 7
7 1
1 8
8 9
9 1
 3 1
1 2
 10 5
5 7
4 8
9 10
7 10
6 10
 15 15
1 2
1 3
1 4
1 5
2 6
2 7
7 8
7 9
3 10
10 11
4 12
12 13
13 14
13 15
15 1
 4 3
1 2
2 3
3 1
 10 30
4 9
4 6
1 2
8 10
7 8
4 7
1 8
6 7
5 6
1 5
7 9
1 7
8 9
7 10
9 10
3 9
2 7
5 7
5 9
2 8
2 9
5 8
3 10
1 6
3 6
2 10
6 8
3 4
2 5
4 5
 4 3
1 2
1 3
1 4
 4 6
1 2
2 3
3 4
4 1
1 3
2 4
 10 9
1 2
1 3
1 4
2 5
5 6
2 7
3 8
3 9
9 10
 10 10
1 2
2 3
3 4
4 5
5 6
6 7
7 8
8 9
9 10
10 1
 3 0
 6 6
1 2
2 3
3 1
4 5
5 6
6 4
 10 0
 9 15
1 2
2 3
3 1
1 4
4 5
5 1
1 6
6 7
7 1
1 8
8 9
9 1
2 9
7 4
2 8
 4 0
 1 0

1
 0
 43
 0
 8
 0
 84
 82
 63
 166666166667000000
 21
 30
 292
 64
 36
 0
 84
 284
 1
 37
 1
 4
 59
 50
 1
 2
 120
 28
 4
 0

#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> graph(1000006);
int csum[1000006];
int main() {
  ios_base::sync_with_stdio(false);
  int i, j, k, n, x, q, y, m;
  cin >> n >> m;
  for (i = 0; i < m; i++) {
    cin >> x >> y;
    graph[x].push_back(y);
    graph[y].push_back(x);
    if (min(x, y) + 1 == max(x, y)) {
      csum[max(x, y)] = 1;
    }
  }
  if (n <= 2) {
    cout << 0;
    return 0;
  }
  for (i = 1; i <= n; i++) {
    csum[i] += csum[i - 1];
  }
  long long ans = 0;
  for (i = 1; i <= n; i++) {
    sort(graph[i].begin(), graph[i].end());
    int last = i;
    for (j = 0; j < graph[i].size(); j++) {
      if (graph[i][j] < i) continue;
      if (last != i && graph[i][j] == 1 + last &&
          csum[graph[i][j]] != csum[last])
        ans++;
      else {
        last++;
        ans +=
            (graph[i][j] - 1 - (last)) - (csum[graph[i][j] - 1] - csum[last]);
      }
      last = graph[i][j];
    }
    last++;
    if (last < n) {
      ans += (n - last) - (csum[n] - csum[last]);
    }
    last = i;
    for (j = graph[i].size() - 1; j >= 0; j--) {
      if (graph[i][j] > i) continue;
      if (last != i && graph[i][j] == last - 1 &&
          csum[graph[i][j]] != csum[last])
        ans++;
      else {
        last--;
        ans +=
            (last - (graph[i][j] + 1)) - (csum[last] - csum[graph[i][j] + 1]);
      }
      last = graph[i][j];
    }
    last--;
    if (last > 0) {
      ans += (last - 1) - (csum[last] - csum[1]);
    }
  }
  for (i = 3; i <= n; i++) {
    if ((csum[i] == csum[i - 1] && csum[i] == csum[i - 2]) ||
        (csum[i] != csum[i - 1] && csum[i - 1] != csum[i - 2]))
      ans--;
  }
  cout << ans << endl;
  return 0;
}
