/// Solution No.:

/// Approach:

/// Comment:

/// Verdict:

/// Report:


#include <iostream>
#include <cmath>
#include <algorithm>
#include <iomanip>
#include <string>
#include <sstream>
#include <cstdio>
#include <vector>
#include <string>
#include <map>
#include <queue>
#include <deque>
#include <bitset>
#include <string.h>
#include <climits>
#include <set>
#include <cassert>
#include <cfloat>
#include <stack>

///using namespace std;         /// Recommended not to use

#define p(x) std::cout<<#x<<" = "<<x<<"\n"
#define mem(a,b) memset(a,b,sizeof(a))
#define mod 1000000007
#define absolute(x) (((x)<0)?(-(x)):(x))
/// #define _DEBUG

typedef long long int ll;
typedef unsigned long long llu;
typedef long double lld;

/// lld pi = 2 * acos(0.0);   /// precision error
lld pi = 2 * acosl(0.0);

int test_case_number, test_case=1;

#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
//	freopen("output.txt", "w", stdout);
#endif
/// Direction Array
/// int dx[]={0, 0, 1, -1, -1, 1, -1, 1};
/// int dy[]={-1, 1, 0, 0, 1, 1, -1, -1};

///place for problem specific functions


void function_name()
{
    int elemen_number;
    scanf("%d", &elemen_number);
    bool is_zero = false, limit_exceeded = false;
    std::vector<ll> main_array(elemen_number);
    for(int i=0;i<elemen_number;i++)
    {
        scanf("%lld", &main_array[i]);
        if(main_array[i]== 0LL)
        {
            is_zero = true;
        }
    }
    ll answer=1LL, limit = 1e18L;
    //printf("%lld\n", limit);
    for(int i=0;i<elemen_number;i++)
    {
        if(main_array[i]<= limit/answer)
        {
            answer *= main_array[i];
        }
        else
        {
            limit_exceeded = true;
            break;
        }
    }
    if(is_zero)
    {
        printf("0\n");
    }
    else if(limit_exceeded)
    {
        printf("-1\n");
    }
    else
    {
        printf("%lld\n", answer);
    }

}
void function_name(int v1, int v2, int v3)
{

}
void function_name(std::string line)
{

}
class initial_works
{
public:

    void with_test_case_number()
    {
        scanf("%d", &test_case_number);
        ///getchar();
        while(test_case <= test_case_number)
        {
            function_name();
            test_case++;
        }
    }

    void single_iteration()
    {
        function_name();
    }

    void without_test_case_number()
    {
        int v1, v2, v3;
        while(scanf("%d %d %d", &v1, &v2, &v3)==3 && v1!=0)
        {
            function_name(v1, v2, v3);
            test_case++;
        }
    }

    void eoof()
    {
        char dummy_char_array[100];
        while(scanf("%[^\n]", dummy_char_array)!=EOF)
        {
            ///it only takes the absence of one getchar to ruin your life. Don't understand remove the getchar below and then input the sample input
            getchar();
            ///if not given getchar. the dummu_char_array will not take new input as there is newline after the first input is taken. It will continue with the previous value.
            /// So, the function will run with same argument.
            std::string line = dummy_char_array;
            function_name(line);
            test_case++;
        }
    }
};


int main()
{
    //std::ios_base::sync_with_stdio(false);
    initial_works a;
    a.single_iteration();

    return 0;
}



Measured memory_bytes: 4072