#include <stdio.h>
#include <stdlib.h>

int cmp_ll (const void *ap, const void *bp) {
  long long a = *(long long *)ap;
  long long b = *(long long *)bp;
  
  if (a < b) {
    return -1;
  }
  
  if (a > b) {
    return 1;
  }
  
  return 0;
}

long long power_mod (long long a, long long b, long long mod_num) {
  long long ans = 1LL;
  
  if (b > 0LL) {
    ans = power_mod(a, b/2LL, mod_num);
    ans = (ans * ans) % mod_num;
    if (b%2LL == 1LL) {
      ans = (ans * a) % mod_num;
    }
  }
  
  return ans;
}

int main () {
  int n = 0;
  int q = 0;
  int l = 0;
  int r = 0;
  
  int res = 0;
  
  long long ans = 1LL;
  long long mod_num = 998244353LL;
  
  long long s[200001] = {};
  
  int cnt = 0;
  int is_ok = 1;
  
  long long fact[200002] = {};
  long long invf[200002] = {};
  
  res = scanf("%d", &n);
  res = scanf("%d", &q);
  for (int i = 0; i < q; i++) {
    res = scanf("%d", &l);
    res = scanf("%d", &r);
    s[l-1] |= (1LL<<((long long)i));
    s[r] |= (1LL<<((long long)i));
  }
  
  fact[0] = 1LL;
  for (int i = 0; i <= n; i++) {
    fact[i+1] = fact[i];
    fact[i+1] *= (long long) (i+1);
    fact[i+1] %= mod_num;
  }
  
  invf[n+1] = power_mod(fact[n+1], mod_num-2LL, mod_num);
  for (int i = n+1; i > 0; i--) {
    invf[i-1] = invf[i];
    invf[i-1] *= (long long) i;
    invf[i-1] %= mod_num;
  }
  
  for (int i = 1; i < n; i++) {
    s[i] = (s[i]^s[i-1]);
  }
  
  qsort(s, n, sizeof(long long), cmp_ll);
  
  cnt = 1;
  s[n] = -1LL;
  for (int i = 1; i <= n; i++) {
    if (s[i] != s[i-1]) {
      if (s[i-1] != 0LL && cnt%2 == 1) {
        is_ok = 0;
      } else if (cnt%2 == 1) {
        long long tmp1 = fact[cnt+1];
        long long tmp2 = fact[cnt+1];
        tmp1 *= invf[(cnt+1)/2];
        tmp1 %= mod_num;
        tmp1 *= invf[(cnt+1)/2];
        tmp1 %= mod_num;
        tmp2 *= invf[(cnt+3)/2];
        tmp2 %= mod_num;
        tmp2 *= invf[(cnt-1)/2];
        tmp2 %= mod_num;
        ans *= tmp1+mod_num-tmp2;
        ans %= mod_num;
      } else {
        long long tmp1 = fact[cnt];
        long long tmp2 = fact[cnt];
        tmp1 *= invf[cnt/2];
        tmp1 %= mod_num;
        tmp1 *= invf[cnt/2];
        tmp1 %= mod_num;
        tmp2 *= invf[1+cnt/2];
        tmp2 %= mod_num;
        tmp2 *= invf[cnt/2-1];
        tmp2 %= mod_num;
        ans *= tmp1+mod_num-tmp2;
        ans %= mod_num;
      }
      cnt = 0;
    }
    cnt++;
  }
  
  if (is_ok <= 0) {
    printf("0\n");
    return 0;
  }
  
  ans *= fact[n/2];
  ans %= mod_num;
  ans *= fact[n-n/2];
  ans %= mod_num;
  
  printf("%lld\n", ans);
  return 0;
}