import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = (1 << 63)-1
# inf = (1 << 31)-1
# md = 10**9+7
md = 998244353

def nHr(hn, hr):
    return nCr(hn+hr-1, hr-1)

def nPr(com_n, com_r):
    if com_r < 0: return 0
    if com_n < com_r: return 0
    return fac[com_n]*ifac[com_n-com_r]%md

def nCr(com_n, com_r):
    if com_r < 0: return 0
    if com_n < com_r: return 0
    return fac[com_n]*ifac[com_r]%md*ifac[com_n-com_r]%md

n_max = 200005
fac = [1]
for i in range(1, n_max+1): fac.append(fac[-1]*i%md)
ifac = [1]*(n_max+1)
ifac[n_max] = pow(fac[n_max], md-2, md)
for i in range(n_max-1, 1, -1): ifac[i] = ifac[i+1]*(i+1)%md

def cata(n):
    return (nCr(2*n, n)-nCr(2*n, n-1))%md

from collections import Counter

n, q = LI()
ss = [0]*(n+1)
for i in range(q):
    l, r = LI()
    l -= 1
    ss[l] |= 1 << i
    ss[r] |= 1 << i

for i in range(n): ss[i+1] ^= ss[i]
sc = Counter(ss[:-1])

ans = 1
for s, c in sc.items():
    if s == 0: continue
    if c & 1:
        print(0)
        exit()
    ans *= cata(c//2)
    ans %= md
c = sc[0]
ans *= nCr(c, c//2)-nCr(c, c//2-1)
ans %= md
ans *= fac[n//2]*fac[n-n//2]%md
ans %= md

print(ans)