#include <bits/stdc++.h>

using namespace std;
using ll = long long;

constexpr ll mod = 998244353;

template<ll mod>
struct Mint {
  using M=Mint; ll v;
  M& put(ll x) { v=(x<mod)?x:x-mod; return *this; }
  Mint(ll x=0) { put(x%mod+mod); }
  M operator+(M m) {return M().put(v+m.v);}
  M operator-(M m) {return M().put(v+mod-m.v);}
  M operator*(M m) {return M().put(v*m.v%mod);}
  M operator/(M m) {return M().put(v*m.inv().v%mod);}
// BEGIN IGNORE
  M operator+=(M m) { return put(v+m.v); }
  M operator-=(M m) { return put(v+mod-m.v); }
  M operator*=(M m) { return put(v*m.v%mod); }
  M operator/=(M m) { return put(v*m.inv().v%mod); }
// END IGNORE
  bool operator==(M m) { return v==m.v; }
  M pow(ll m) const {
    M x=v, res=1;
    while (m) {
      if (m&1) res=res*x;
      x=x*x; m>>=1;
    }
    return res;
  }
  M inv() { return pow(mod-2); }
};

using mint = Mint<mod>;

struct UnionFind{
  int n;
  vector<int> par;
  UnionFind(int n) : n(n), par(n, -1){}
  int find(int x){return par[x] < 0 ? x : find(par[x]);}
  bool Unite(int x, int y){
    x = find(x), y = find(y);
    if(x == y)return false;
    // size[x] < size[y]
    if(par[x] > par[y])swap(x, y);
    par[x] += par[y];
    par[y] = x;
    return true;
  }
};

namespace std {
  template<typename T,typename U> struct hash<pair<T,U>> {
    size_t operator()(pair<T,U> const &val) const {
      return hash<T>{}(val.first)*1337^hash<U>{}(val.second);
    }};
}

int main(){

  int n;
  cin >> n;
  vector<int> a(n);
  for(int i = 0; i < n; ++i){
    cin >> a[i];
  }
  int cn = 0;
  for(int i = 0; i < n; ++i){
    if(a[i] == 1 && a[(i + 1) % n] == 0){
      ++cn;
    }
  }
  cout << (mint(cn) * mint(n).inv()).v << endl;

}