#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
using namespace std;
using ll=long long;
#define double long double
using datas=pair<ll,ll>;
using ddatas=pair<double,double>;
using tdata=pair<ll,datas>;
using vec=vector<ll>;
using mat=vector<vec>;
using pvec=vector<datas>;
using pmat=vector<pvec>;
// using llset=tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>;
#define For(i,a,b) for(i=a;i<(ll)b;++i)
#define bFor(i,b,a) for(i=b,--i;i>=(ll)a;--i)
#define rep(i,N) For(i,0,N)
#define rep1(i,N) For(i,1,N)
#define brep(i,N) bFor(i,N,0)
#define brep1(i,N) bFor(i,N,1)
#define all(v) (v).begin(),(v).end()
#define allr(v) (v).rbegin(),(v).rend()
#define vsort(v) sort(all(v))
#define vrsort(v) sort(allr(v))
#define endl "\n"
#define eb emplace_back
#define print(x) cout<<x<<endl
#define printyes print("Yes")
#define printno print("No")
#define printYES print("YES")
#define printNO print("NO")
#define output(v) do{bool f=0;for(auto outi:v){cout<<(f?" ":"")<<outi;f=1;}cout<<endl;}while(0)
#define matoutput(v) do{for(auto outimat:v)output(outimat);}while(0)
const ll mod=1000000007;
// const ll mod=998244353;
const ll inf=1LL<<60;
const double PI=acos(-1);
const double eps=1e-9;
template<class T,class E> ostream& operator<<(ostream& os,pair<T,E>& p){return os<<"{"<<p.first<<","<<p.second<<"}";}
template<class T> inline bool chmax(T& a,T b){bool x=a<b;if(x)a=b;return x;}
template<class T> inline bool chmin(T& a,T b){bool x=a>b;if(x)a=b;return x;}

ll modinv(ll a,ll m=mod) {
  ll b=m,u=1,v=0,t;
  while(b){
    t=a/b;
    a-=t*b; swap(a,b);
    u-=t*v; swap(u,v);
  }
  return (u+m)%m;
}

ll moddevide(ll a,ll b){return (a*modinv(b))%mod;}

ll modpow(ll a,ll n,ll m=mod){
  ll res=1;
  while(n>0){
    if(n&1)res=res*a%m;
    a=a*a%m;
    n>>=1;
  }
  return res;
}

ll N;
ll ans=1;
int main(){
  ll i,j,k;
  // rep1(i,500000003){
  //   (j*=i)%=500000003;
  //   if(i%100000==0){
  //     print(j);
  //   }
  // }
  // mat g(5001,vec(1,1));
  // rep(i,calc.size()){
  //   g[i+1][0]=calc[i];
  // }
  cin>>N;
  vec v(N);
  rep(i,N)cin>>v[i];
  if(!*min_element(all(v))){
    print(-1);
    return 0;
  }
  if(*max_element(all(v))>=4){
    print(mod);
  }else{
    vec calc={1,1,4,729};
    rep(i,N){
      ans*=calc[v[i]];
      if(ans>mod)break;
    }
    if(i==N){
      print(mod%ans);
    }else{
      print(mod);
    }
  }
  // rep(i,N){
  //   if(v[i]==1||v[i]>=500000003)continue;
  //   j=v[i]/100000;
  //   k=v[i]%100000;
  //   if((int)g[j].size()<k){
  //     ll x;
  //     For(x,g[j].size(),k+1){
  //       g[j].eb(g[j].back()*(j*100000+x)%500000003);
  //     }
  //   }
  //   k=g[j][k];
  //   if(k&1)k<<=1;
  //   print(k);print(modpow(v[i],k));
  //   (ans*=modpow(v[i],k))%=mod;
  // }
  // print(ans);
}