#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
int add[300005];
int l[300005], r[300005];
long long f1[300005], f2[300005];
long long pow_inv(long long a) {
  long long ans = 1, b = mod - 2;
  while (b) {
    if (b % 2 == 1) ans = ans * a % mod;
    a = a * a % mod;
    b /= 2;
  }
  return ans;
}
long long nCr(int a, int b) {
  if (a < b || a < 0 || b < 0) return 0;
  return f1[a] * 1ll * f2[b] % mod * f2[a - b] % mod;
}
int a[25], b[25];
int dp[300005][45];
bool vis[300005];
int main() {
  f1[0] = f2[0] = 1;
  for (int i = 1; i <= 300000; i++) {
    f1[i] = f1[i - 1] * i % mod;
    f2[i] = pow_inv(f1[i]);
  }
  int n, m;
  scanf("%d%d", &n, &m);
  for (int i = 1; i <= n; i++)
    scanf("%d%d", &l[i], &r[i]), add[l[i]]++, add[r[i] + 1]--;
  for (int i = 0; i < m; i++) scanf("%d%d", &a[i], &b[i]);
  int cnt = 0;
  for (int i = 1; i <= n; i++) {
    cnt += add[i];
    for (int j = 0; j <= m + m; j++) {
      long long res = nCr(cnt - j, i - j);
      dp[i][j] = (dp[i - 1][j] + nCr(cnt - j, i - j)) % mod;
    }
  }
  long long ans = 0;
  for (int i = 0; i < (1 << m); i++) {
    int L = 1, R = n, cnt = 0;
    for (int j = 0; j < m; j++) {
      if ((i >> j) & 1) {
        L = max(L, l[a[j]]);
        R = min(R, r[a[j]]);
        L = max(L, l[b[j]]);
        R = min(R, r[b[j]]);
        if (!vis[a[j]]) cnt++;
        if (!vis[b[j]]) cnt++;
        vis[a[j]] = 1;
        vis[b[j]] = 1;
      }
    }
    if (L <= R) {
      long long res = (dp[R][cnt] - dp[L - 1][cnt] + mod) % mod;
      if (__builtin_popcount(i) % 2 == 0)
        ans = (ans + res) % mod;
      else
        ans = (ans - res + mod) % mod;
    }
    for (int j = 0; j < m; j++) {
      if ((i >> j) & 1) {
        vis[a[j]] = 0;
        vis[b[j]] = 0;
      }
    }
  }
  printf("%lld\n", ans);
}
