#include<bits/stdc++.h>
#define fr(i,j,k) for(register int i=j;i<=k;++i)
#define rf(i,j,k) for(register int i=j;i>=k;--i)
#define foredge(i,j) for(register int i=head[j];i;i=e[i].nxt)
#define pb push_back
#define Times printf("Time:%.3lf\n",clock()/CLOCKS_PER_SEC)
using namespace std;
inline int read(){
	int x=0;
	bool f=0;
	char c=getchar();
	while(!isdigit(c)) f|=(c=='-'),c=getchar();
	while(isdigit(c)) x=(x<<3)+(x<<1)+(c^48),c=getchar();
	return f?-x:x;
}
inline void write(int x){
    if(x<0){putchar('-');x=-x;}
    if(x>9)write(x/10);
    putchar(x%10+'0');
}
inline void writeln(int x){write(x); puts("");}
inline void writepl(int x){write(x); putchar(' ');}
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
inline int randfind(int l,int r){return rnd()%(r-l+1)+l;}
//inline void init(){
//	int t=read();
//	while(t--) work();
//}
const int Maxn=1e6+10,mod=998244353;
inline int ksm(int x,int y=mod-2){
    int sum=1;
    while(y){
        if(y&1) sum=1ll*sum*x%mod;
        y=y/2;x=1ll*x*x%mod;
    }
    return sum;
}
inline void add(int &x,int y){
    x+=y;if(x>=mod) x-=mod;
}
int fac[Maxn],ifac[Maxn];
int n;
inline void init(){
    n=read();
    fac[0]=ifac[0]=1;
    fr(i,1,n) fac[i]=1ll*fac[i-1]*i%mod;ifac[n]=ksm(fac[n]);
    rf(i,n-1,1) ifac[i]=1ll*ifac[i+1]*(i+1)%mod;
}
int f[Maxn];
inline int C(int x,int y){
    if(x<0 || y<0 || x<y) return 0;
    return 1ll*fac[x]*ifac[y]%mod*ifac[x-y]%mod;
}
inline void work(){
    f[1]=1;
    fr(i,2,n) f[i]=1ll*(2*i-3)*f[i-1]%mod;
    int ans=0;
    fr(i,1,n){
        int x=read();
        if(!x) continue;
        add(ans,1ll*f[i]*f[n-i+1]%mod*C(n-1,i-1)%mod);
    }
    writeln(ans);
}
signed main(){
	// freopen("input.in","r",stdin);
	// freopen("output.out","w",stdout);
    init();work();
    // printf("\nTIME:%.3lf",(double)clock()/CLOCKS_PER_SEC);
	return 0;
}