#include <iostream>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include<vector>
#include <bitset>
#include <algorithm>
#include <cmath>
#include <tuple>
#include <climits>
#define ll long long
#define ull unsigned long long
#define mod 1000000007
typedef long double ld;
using namespace std;

vector<int> sieve(ll n)
{
	vector<int> a(n+1,0);
	for(ll i=3;i<=n;i+=2)
	a[i]=1;
	for(ll i=3;i<=n;i+=2)
	{
       if(a[i]==1)
	   {
		   for(ll j=i*2;j<=n;j+=i)
		   a[j]=0;
	   }
	}
	a[2]=1;
	a[1]=a[0]=0;
	return a;
}
ll reverse(ll n)
{
	ll s=0;
	while(n>0)
	{
       ll t=n%10;
	   s=s*10+t;
	   n/=10;
	}
	return s;
}
int count_setbits(int N)

{ int cnt=0;

while(N>0)

{

cnt+=(N&1);

N=N>>1;

}

return cnt;

}
ll power(ll x, ll y)  
{  
    int res = 1;     // Initialize result  
  
    x = x % mod; // Update x if it is more than or  
                // equal to p 
   
    if (x == 0) return 0; // In case x is divisible by p; 
  
    while (y > 0)  
    {  
        // If y is odd, multiply x with result  
        if (y & 1)  
            res = (res*x) % mod;  
  
        // y must be even now  
        y = y>>1; // y = y/2  
        x = (x*x) % mod;  
    }  
    return res;  
}  

void BellmanFord(vector< vector<ll> > &graph, int V, int E, int src) 
{ 
    // Initialize distance of all vertices as infinite. 
    int dis[V]; 
    for (int i = 0; i < V; i++) 
        dis[i] = INT_MAX; 
  
    // initialize distance of source as 0 
    dis[src] = 0; 
  
    // Relax all edges |V| - 1 times. A simple 
    // shortest path from src to any other 
    // vertex can have at-most |V| - 1 edges 
    for (int i = 0; i < V - 1; i++) { 
  
        for (int j = 0; j < E; j++) { 
            if (dis[graph[j][0]] + graph[j][2] < 
                               dis[graph[j][1]]) 
                dis[graph[j][1]] =  
                  dis[graph[j][0]] + graph[j][2]; 
        } 
    } 
  
    // check for negative-weight cycles. 
    // The above step guarantees shortest 
    // distances if graph doesn't contain 
    // negative weight cycle.  If we get a 
    // shorter path, then there is a cycle. 
    for (int i = 0; i < E; i++) { 
        int x = graph[i][0]; 
        int y = graph[i][1]; 
        int weight = graph[i][2]; 
        if (dis[x] != INT_MAX && 
                   dis[x] + weight < dis[y]) 
            cout << "Graph contains negative"
                    " weight cycle"
                 << endl; 
    } 
  
    
} 

ll find_binary_rotated(vector<ll> &a,ll key)
{
 ll start=0;ll end=a.size()-1;
 while(start<=end)
 {
	 ll mid=(start+end)/2;
	 if(key==a[mid])
	 return mid;
	 else if(a[start]<=a[mid])
	 {
		 if(key>=a[start] && key<=a[mid])
		 end=mid-1;
		 else
		 {
			 start=mid+1;
		 }
		 
	 }
	 else
	 {
		 if(key>=a[mid] && key<=a[end])
		 start=mid+1;
		 else
		 {
			 end=mid-1;
		 }
		 
	 }
	 
 }
 return -1;
}



int main()
{
	
		int n;
cin >> n;
ll t;
ld ans = 1;
for (int i = 0; i < n; i++)
{
    cin >> t;
    if (ans != -1)
       ans *= t;
    if (ans > 1000000000000000000 || ans < 0)
       ans = -1;
    if (t == 0)
       ans = 0;
}
cout << (ll)ans;
return 0;

		

		

	


		

		
		
		

		
		
	
	
	


	
	
}

Measured memory_bytes: 3644