#include <bits/stdc++.h>
using namespace std;
char buf[25];
struct node {
  long long x, y;
  bool operator<(node tp) const {
    if (x != tp.x) return x < tp.x;
    return y < tp.y;
  }
};
map<long long, long long> h1, h2;
map<node, long long> t, q;
const long long inf = 1e17;
const long long maxn = 2000010;
long long L1[maxn], R1[maxn], l1[maxn], r1[maxn], s1[maxn], a[maxn];
long long L2[maxn], R2[maxn], l2[maxn], r2[maxn], s2[maxn];
long long n, m, sum1, sum2;
long long ans;
long long read() {
  long long x = 0, f = 0;
  char ch;
  do {
    ch = getchar();
    if (ch == '-') f = 1;
  } while (ch < '0' || ch > '9');
  while (ch >= '0' && ch <= '9') {
    x = (x << 1) + (x << 3) + (ch ^ 48);
    ch = getchar();
  }
  return f ? -x : x;
}
void write(long long x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  if (!x) {
    putchar('0');
    return;
  }
  long long cnt = 0;
  while (x) {
    buf[++cnt] = '0' + x % 10;
    x /= 10;
  }
  for (long long i = cnt; i >= 1; --i) putchar(buf[i]);
}
signed main() {
  srand(19267180);
  n = read();
  m = read();
  for (long long i = 1; i <= n; ++i) {
    h1[i] = (1ll * rand() * rand() * rand() * rand() % inf + inf) % inf;
    h2[i] = (1ll * rand() * rand() * rand() * rand() % inf + inf) % inf;
    sum1 = h1[i] ^ sum1;
    sum2 = h2[i] ^ sum2;
  }
  for (long long i = 1; i <= n; ++i) {
    long long l = read(), r = read();
    ++a[l];
    --a[r + 1];
    s1[l] ^= h1[i];
    s1[r + 1] ^= h1[i];
    L1[l - 1] ^= h1[i];
    R1[r + 1] ^= h1[i];
    s2[l] ^= h2[i];
    s2[r + 1] ^= h2[i];
    L2[l - 1] ^= h2[i];
    R2[r + 1] ^= h2[i];
  }
  for (long long i = m - 1; i >= 1; --i) L1[i] ^= L1[i + 1], L2[i] ^= L2[i + 1];
  for (long long i = 2; i <= m; ++i) {
    R1[i] ^= R1[i - 1], s1[i] ^= s1[i - 1];
    R2[i] ^= R2[i - 1], s2[i] ^= s2[i - 1];
  }
  for (long long i = 2; i <= m; ++i) s1[i] ^= s1[i - 1], s2[i] ^= s2[i - 1];
  for (long long i = 1; i <= m; ++i) {
    l1[i] = s1[i - 1] ^ R1[i], r1[i] = s1[i] ^ L1[i];
    l2[i] = s2[i - 1] ^ R2[i], r2[i] = s2[i] ^ L2[i];
  }
  for (long long i = m; i >= 1; --i) {
    t[(node){r1[i], r2[i]}] += 1;
    q[(node){r1[i], r2[i]}] += i;
    long long x_1 = sum1 ^ l1[i], x_2 = sum2 ^ l2[i];
    ans += q[(node){x_1, x_2}] - 1ll * t[(node){x_1, x_2}] * (i - 1);
  }
  for (long long i = 1; i <= m; ++i) a[i] += a[i - 1];
  long long x = 0;
  for (long long i = 1; i <= m; ++i) {
    if (a[i] == 0)
      ++x;
    else
      x = 0;
    if (x)
      if (i == m || a[i + 1] != 0)
        for (long long j = 1; j <= x; ++j) ans -= 1ll * j * (x - j + 1);
  }
  write(ans);
  return 0;
}
