import sys
input = sys.stdin.readline
def read_values(): return tuple(map(int, input().split()))

class FFT():
    def primitive_root_constexpr(self,m):
        if m==2:return 1
        if m==167772161:return 3
        if m==469762049:return 3
        if m==754974721:return 11
        if m==998244353:return 3
        divs=[0]*20
        divs[0]=2
        cnt=1
        x=(m-1)//2
        while(x%2==0):x//=2
        i=3
        while(i*i<=x):
            if (x%i==0):
                divs[cnt]=i
                cnt+=1
                while(x%i==0):
                    x//=i
            i+=2
        if x>1:
            divs[cnt]=x
            cnt+=1
        g=2
        while(1):
            ok=True
            for i in range(cnt):
                if pow(g,(m-1)//divs[i],m)==1:
                    ok=False
                    break
            if ok:
                return g
            g+=1
    def bsf(self,x):
        res=0
        while(x%2==0):
            res+=1
            x//=2
        return res
    rank2=0
    root=[]
    iroot=[]
    rate2=[]
    irate2=[]
    rate3=[]
    irate3=[]
    
    def __init__(self,MOD):
        self.mod=MOD
        self.g=self.primitive_root_constexpr(self.mod)
        self.rank2=self.bsf(self.mod-1)
        self.root=[0 for i in range(self.rank2+1)]
        self.iroot=[0 for i in range(self.rank2+1)]
        self.rate2=[0 for i in range(self.rank2)]
        self.irate2=[0 for i in range(self.rank2)]
        self.rate3=[0 for i in range(self.rank2-1)]
        self.irate3=[0 for i in range(self.rank2-1)]
        self.root[self.rank2]=pow(self.g,(self.mod-1)>>self.rank2,self.mod)
        self.iroot[self.rank2]=pow(self.root[self.rank2],self.mod-2,self.mod)
        for i in range(self.rank2-1,-1,-1):
            self.root[i]=(self.root[i+1]**2)%self.mod
            self.iroot[i]=(self.iroot[i+1]**2)%self.mod
        prod=1;iprod=1
        for i in range(self.rank2-1):
            self.rate2[i]=(self.root[i+2]*prod)%self.mod
            self.irate2[i]=(self.iroot[i+2]*iprod)%self.mod
            prod=(prod*self.iroot[i+2])%self.mod
            iprod=(iprod*self.root[i+2])%self.mod
        prod=1;iprod=1
        for i in range(self.rank2-2):
            self.rate3[i]=(self.root[i+3]*prod)%self.mod
            self.irate3[i]=(self.iroot[i+3]*iprod)%self.mod
            prod=(prod*self.iroot[i+3])%self.mod
            iprod=(iprod*self.root[i+3])%self.mod
    def butterfly(self,a):
        n=len(a)
        h=(n-1).bit_length()
        
        LEN=0
        while(LEN<h):
            if (h-LEN==1):
                p=1<<(h-LEN-1)
                rot=1
                for s in range(1<<LEN):
                    offset=s<<(h-LEN)
                    for i in range(p):
                        l=a[i+offset]
                        r=a[i+offset+p]*rot
                        a[i+offset]=(l+r)%self.mod
                        a[i+offset+p]=(l-r)%self.mod
                    rot*=self.rate2[(~s & -~s).bit_length()-1]
                    rot%=self.mod
                LEN+=1
            else:
                p=1<<(h-LEN-2)
                rot=1
                imag=self.root[2]
                for s in range(1<<LEN):
                    rot2=(rot*rot)%self.mod
                    rot3=(rot2*rot)%self.mod
                    offset=s<<(h-LEN)
                    for i in range(p):
                        a0=a[i+offset]
                        a1=a[i+offset+p]*rot
                        a2=a[i+offset+2*p]*rot2
                        a3=a[i+offset+3*p]*rot3
                        a1na3imag=(a1-a3)%self.mod*imag
                        a[i+offset]=(a0+a2+a1+a3)%self.mod
                        a[i+offset+p]=(a0+a2-a1-a3)%self.mod
                        a[i+offset+2*p]=(a0-a2+a1na3imag)%self.mod
                        a[i+offset+3*p]=(a0-a2-a1na3imag)%self.mod
                    rot*=self.rate3[(~s & -~s).bit_length()-1]
                    rot%=self.mod
                LEN+=2
                
    def butterfly_inv(self,a):
        n=len(a)
        h=(n-1).bit_length()
        LEN=h
        while(LEN):
            if (LEN==1):
                p=1<<(h-LEN)
                irot=1
                for s in range(1<<(LEN-1)):
                    offset=s<<(h-LEN+1)
                    for i in range(p):
                        l=a[i+offset]
                        r=a[i+offset+p]
                        a[i+offset]=(l+r)%self.mod
                        a[i+offset+p]=(l-r)*irot%self.mod
                    irot*=self.irate2[(~s & -~s).bit_length()-1]
                    irot%=self.mod
                LEN-=1
            else:
                p=1<<(h-LEN)
                irot=1
                iimag=self.iroot[2]
                for s in range(1<<(LEN-2)):
                    irot2=(irot*irot)%self.mod
                    irot3=(irot*irot2)%self.mod
                    offset=s<<(h-LEN+2)
                    for i in range(p):
                        a0=a[i+offset]
                        a1=a[i+offset+p]
                        a2=a[i+offset+2*p]
                        a3=a[i+offset+3*p]
                        a2na3iimag=(a2-a3)*iimag%self.mod
                        a[i+offset]=(a0+a1+a2+a3)%self.mod
                        a[i+offset+p]=(a0-a1+a2na3iimag)*irot%self.mod
                        a[i+offset+2*p]=(a0+a1-a2-a3)*irot2%self.mod
                        a[i+offset+3*p]=(a0-a1-a2na3iimag)*irot3%self.mod
                    irot*=self.irate3[(~s & -~s).bit_length()-1]
                    irot%=self.mod
                LEN-=2
    def convolution(self,a,b):
        n=len(a);m=len(b)
        if not(a) or not(b):
            return []
        if min(n,m)<=40:
            res=[0]*(n+m-1)
            for i in range(n):
                for j in range(m):
                    res[i+j]+=a[i]*b[j]
                    res[i+j]%=self.mod
            return res
        z=1<<((n+m-2).bit_length())
        a=a+[0]*(z-n)
        b=b+[0]*(z-m)
        self.butterfly(a)
        self.butterfly(b)
        c=[(a[i]*b[i])%self.mod for i in range(z)]
        self.butterfly_inv(c)
        iz=pow(z,self.mod-2,self.mod)
        for i in range(n+m-1):
            c[i]=(c[i]*iz)%self.mod
        return c[:n+m-1]

mod=998244353
fft=FFT(mod)

def powfft(f,n):
    if n==1:
        return f
    ff=fft.convolution(f,f)
    res=powfft(ff,n//2)
    if n%2==1:
        res=fft.convolution(res,f)
    return res

def bin(a,b,f,rf):
    if a<0 or b<0 or a<b:
        return 0
    return f[a]*rf[b]%mod*rf[a-b]%mod

def main():  
    n,m=read_values()
    c={}
    for _ in range(m):
        l,r=read_values()
        c[r-l+1]=c.get(r-l+1,0)+1
    if n%2:
        print(0)
        return
    f=[1]*(n+1)
    rf=[1]*(n+1)
    r=[1]*(n+1)
    for i in range(n):
        f[i+1]=f[i]*(i+1)%mod
        rf[i+1]=pow(f[i+1],-1,mod)
        r[i+1]=pow(i+1,-1,mod)
    
    p=[1]
    for k,v in c.items():
        if k%2==1 or v==0:
            continue
        mul=[0]*(k//2+1)
        mul[0]=1
        mul[k//2]=-bin(k,k//2,f,rf)*r[k//2+1]%mod
        if v==1:
            pp=[0]*(len(p)+k//2)
            for i in range(len(p)):
                pp[i]=(pp[i]+p[i])%mod
                pp[i+k//2]=(pp[i+k//2]+p[i]*mul[k//2])%mod
            p=pp
        else:
            res=powfft(mul,v)
            p=fft.convolution(p,res)
    ans=0
    for i in range(len(p)):
        ans+=p[i]*bin(n-i*2,n//2-i,f,rf)*r[n//2-i+1]%mod
        ans%=mod
    print(ans)
        
if __name__ == "__main__":
    main()