MAX = 1000000 fac = [0]*(MAX+1) inv = [0]*(MAX+1) finv = [0]*(MAX+1) mod = 998244353 fac[0] = fac[1] = finv[0] = finv[1] = inv[1] = 1 for i in range(2,MAX+1): fac[i] = fac[i-1]*i%mod inv[i] = mod-inv[mod%i]*(mod//i)%mod finv[i] = finv[i-1]*inv[i]%mod def binom(n,r): if r<0 or n<0 or n<r: return 0 return fac[n]*finv[r]%mod*finv[n-r]%mod N,Q = map(int,input().split()) mem = [0]*(N+1) for i in range(Q): L,R = map(int,input().split()) mem[L-1] ^= (1<<i) mem[R] ^= (1<<i) now = 0 cnt = dict() for i in range(N): now ^= mem[i] if now in cnt: cnt[now] += 1 else: cnt[now] = 1 ans = fac[N//2]*fac[N-N//2]%mod for el in cnt: val = cnt[el] if val % 2: if el: ans = 0 val += 1 ans *= fac[val]*finv[val//2]%mod*finv[val//2+1]%mod ans %= mod print(ans)