#include<bits/stdc++.h>
using namespace std;
long long n,a[1000010],p=998244353,sum1,sum2,fac[1000010],inv[1000010];
long long qpow(long long a,long long b){
	long long res=1;
	while(b!=0){
		if(b%2==1){
			res=(res*a)%p;
		}
		a=(a*a)%p;
		b/=2;
	}
	return res;
}
long long read(){
	char ch=getchar();
	long long sgn=1,x=0;
	while(ch<'0'||ch>'9'){
		if(ch=='-'){
			sgn=-1;
		}
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		x=(x<<3)+(x<<1)+(ch&15);
		ch=getchar();
	}
	return x*sgn;
}
void write(long long n,bool p){
	if(n<0){
		putchar('-');
		n=-n;
	}
	if(n==0){
		if(p==true){
			putchar('0');
		}
		return;
	}
	write(n/10,0);
	putchar(n%10+'0');
}
int main(){
	fac[0]=1;
	for(int i=1;i<=400000;i++){
		fac[i]=fac[i-1]%p*i%p;
		inv[i]=qpow(fac[i],p-2);
	}
	cin>>n;
	for(int i=1;i<=2*n;i++){
		cin>>a[i];
		a[i]%=p;
	}
	sort(a+1,a+2*n+1);
	for(int i=1;i<=n;i++){
		sum1+=a[i];
		sum1%=p;
	}
	for(int i=n+1;i<=2*n;i++){
		sum2+=a[i];
		sum2%=p;
	}
	cout<<(sum2-sum1)%p*fac[2*n]%p*inv[n]%p*inv[n]%p<<endl;
	// ans=[sum(a[n+1],a[2n])-sum(a[1],a[n])]*C(2n,n);
	return 0;
}

看着好对就是调不出来 求好心人帮忙
WA on 7