Problem:
Score : 500 points

Problem Statement

An adult game master and N children are playing a game on an ice rink.
The game consists of K rounds.
In the i-th round, the game master announces:

Form groups consisting of A_i children each!

Then the children who are still in the game form as many groups of A_i children as possible.
One child may belong to at most one group.
Those who are left without a group leave the game. The others proceed to the next round.
Note that it's possible that nobody leaves the game in some round.

In the end, after the K-th round, there are exactly two children left, and they are declared the winners.

You have heard the values of A_1, A_2, ..., A_K. You don't know N, but you want to estimate it.

Find the smallest and the largest possible number of children in the game before the start, or determine that no valid values of N exist.

Constraints

1 \leq K \leq 10^5

2 \leq A_i \leq 10^9

All input values are integers.

Input

Input is given from Standard Input in the following format:

K
A_1 A_2 ... A_K

Output

Print two integers representing the smallest and the largest possible value of N, respectively,
or a single integer -1 if the described situation is impossible.

Sample Input 1

4
3 4 3 2

Sample Output 1

6 8

For example, if the game starts with 6 children, then it proceeds as follows:

In the first round, 6 children form 2 groups of 3 children, and nobody leaves the game.

In the second round, 6 children form 1 group of 4 children, and 2 children leave the game.

In the third round, 4 children form 1 group of 3 children, and 1 child leaves the game.

In the fourth round, 3 children form 1 group of 2 children, and 1 child leaves the game.

The last 2 children are declared the winners.

Sample Input 2

5
3 4 100 3 2

Sample Output 2

-1

This situation is impossible.
In particular, if the game starts with less than 100 children, everyone leaves after the third round.

Sample Input 3

10
2 2 2 2 2 2 2 2 2 2

Sample Output 3

2 3

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

/*やったぜ。　投稿者：変態糞土方 (8月16日（水）07時14分22秒)

昨日の8月15日にいつもの浮浪者のおっさん（60歳）と先日メールくれた汚れ好きの土方のにいちゃん

（45歳）とわし（53歳）の3人で県北にある川の土手の下で盛りあったぜ。

今日は明日が休みなんでコンビニで酒とつまみを買ってから滅多に人が来ない所なんで、

そこでしこたま酒を飲んでからやりはじめたんや。

3人でちんぽ舐めあいながら地下足袋だけになり持って来たいちぢく浣腸を3本ずつ入れあった。

しばらくしたら、けつの穴がひくひくして来るし、糞が出口を求めて腹の中でぐるぐるしている。

浮浪者のおっさんにけつの穴をなめさせながら、兄ちゃんのけつの穴を舐めてたら、

先に兄ちゃんがわしの口に糞をドバーっと出して来た。

それと同時におっさんもわしも糞を出したんや。もう顔中、糞まみれや、

3人で出した糞を手で掬いながらお互いの体にぬりあったり、

糞まみれのちんぽを舐めあって小便で浣腸したりした。ああ～～たまらねえぜ。

しばらくやりまくってから又浣腸をしあうともう気が狂う程気持ちええんじゃ。

浮浪者のおっさんのけつの穴にわしのちんぽを突うずるっ込んでやると

けつの穴が糞と小便でずるずるして気持ちが良い。

にいちゃんもおっさんの口にちんぽ突っ込んで腰をつかって居る。

糞まみれのおっさんのちんぽを掻きながら、思い切り射精したんや。

それからは、もうめちゃくちゃにおっさんと兄ちゃんの糞ちんぽを舐めあい、

糞を塗りあい、二回も男汁を出した。もう一度やりたいぜ。

やはり大勢で糞まみれになると最高やで。こんな、変態親父と糞あそびしないか。

ああ～～早く糞まみれになろうぜ。

岡山の県北であえる奴なら最高や。わしは163*90*53,おっさんは165*75*60、や

糞まみれでやりたいやつ、至急、メールくれや。

土方姿のまま浣腸して、糞だらけでやろうや。*/
#include "bits/stdc++.h"
#include <numeric>
#define rep(i,n) for(int i = 0; i < n; i++)
typedef long long ll;
typedef unsigned long long ull;
using namespace std;
#define llMAX numeric_limits<long long>::max()
#define intMAX numeric_limits<int>::max()
#define llMIN numeric_limits<long long>::min()
#define intMIN numeric_limits<int>::min()
#define d_5 100000
#define d9_7 1000000007
#define vll vector<vector<long long>>
#define vl vector<long long>
#define vi vector<int>
#define vii vector<vector<int>>
#define pb push_back
#define pf push_front
#define ld long double
ll judge2(ll n){
  ll ans=1;
  while(!(n<ans && ans<=2*n)){
    ans*=2;
  }
  return ans-n;
}

int main(void){
  ll k;
  cin>>k;
  vl a(k);
  rep(i,k){
    cin>>a[i];
  }
  ll nowmax=2;
  ll nowmin=2;
  reverse(a.begin(),a.end());
  rep(i,k){
    ll tmp=(nowmin/a[i])*a[i];
    while(1){
      if(nowmax>=tmp && nowmin<=tmp)break;
      if(nowmax>tmp){
        cout<<-1<<endl;
        return 0;
      }
      tmp+=a[i];
    }
    if(a[i]>nowmax ){
      cout<<-1<<endl;
      return 0;
    }
    ll tmpnowmax=(nowmax/a[i])*a[i];
    nowmax=tmpnowmax+a[i]-1;
    if(a[i]>=nowmin){
      nowmin=a[i];
    }else{
      nowmin=a[i]*((nowmin+a[i]-1)/a[i]);
    }
    /*nowmin=max(a[i],((nowmin + a[i]-1)/a[i])*a[i] );
    nowmax=((nowmax+(a[i]-1))/a[i])*a[i] + -1;*/
  }
  cout<<nowmin<<" "<<nowmax<<endl;
  return 0;
}