#include <bits/stdc++.h>
using namespace std;
const int MAXN = 300005;
const int MAXM = 25;
const int MOD = 998244353;
int n, m, l[MAXN], r[MAXN], a[MAXN], b[MAXN];
long long modpow(long long x, long long p) {
  if (p == 0) return 1;
  if (p % 2 == 1) return x * modpow(x, p - 1) % MOD;
  long long r = modpow(x, p / 2);
  return r * r % MOD;
}
long long modinv(long long x) { return modpow(x, MOD - 2); }
long long fact[MAXN], invfact[MAXN];
long long C(int n, int r) {
  if (r > n || r < 0) return 0;
  return fact[n] * invfact[r] % MOD * invfact[n - r] % MOD;
}
int c[MAXN];
long long pref[2 * MAXM][MAXN];
bool vis[MAXN];
int main() {
  scanf("%d %d", &n, &m);
  fact[0] = 1;
  for (int i = 1; i <= n; i++) fact[i] = i * fact[i - 1] % MOD;
  invfact[n] = modinv(fact[n]);
  for (int i = n - 1; i >= 0; i--) invfact[i] = (i + 1) * invfact[i + 1] % MOD;
  for (int i = 0; i < n; i++) {
    scanf("%d %d", &l[i], &r[i]);
    c[l[i]]++;
    c[r[i] + 1]--;
  }
  for (int i = 2; i <= n; i++) c[i] += c[i - 1];
  for (int i = 0; i < m; i++) {
    scanf("%d %d", &a[i], &b[i]);
    a[i]--, b[i]--;
  }
  for (int j = 0; j <= 2 * m; j++)
    for (int i = 1; i <= n; i++) {
      pref[j][i] = (C(c[i] - j, i - j) + pref[j][i - 1]) % MOD;
    }
  long long res = 0;
  for (int mask = 0; mask < (1 << m); mask++) {
    int cnt = 0, li = 1, ri = n;
    for (int i = 0; i < m; i++)
      if (mask & (1 << i)) {
        if (!vis[a[i]]) {
          vis[a[i]] = true;
          cnt++;
        }
        li = max(li, l[a[i]]);
        ri = min(ri, r[a[i]]);
        if (!vis[b[i]]) {
          vis[b[i]] = true;
          cnt++;
        }
        li = max(li, l[b[i]]);
        ri = min(ri, r[b[i]]);
      }
    for (int i = 0; i < m; i++) {
      vis[a[i]] = false;
      vis[b[i]] = false;
    }
    if (li > ri) continue;
    if (__builtin_popcount(mask) % 2 == 0) {
      res = (res + pref[cnt][ri] - pref[cnt][li - 1] + MOD) % MOD;
    } else {
      res = (res - pref[cnt][ri] + pref[cnt][li - 1] + MOD) % MOD;
    }
  }
  printf("%lld\n", res);
  return 0;
}
