#include<bits/stdc++.h>
using namespace std;
#define int unsigned long long
const int N=1e6+10,M=1e18;
int a[N];
signed main()
{
	int n,f=1;
	cin>>n;
	for(int i=1;i<=n;i++)cin>>a[i];
	sort(a+1,a+n+1);
	if(!a[1])
	{
		cout<<0;
		return 0;
	}
	for(int i=n;i>=1;i--)
	{
	  if(f>(int)(M/a[i]))
	  {
	  	f=0;
	  	break;
	  }
	  f=f*a[i];
	}
	 if(!f)cout<<-1<<'\n';
	 else cout<<f<<'\n';
}

#include<bits/stdc++.h>

using u32 = unsigned;
using i64 = long long;
using u64 = unsigned long long;
using i128 = __int128;

void solve() {
    int n;
    std::cin >> n;

    std::vector<i64> a(n);
    for (auto &i: a) {
        std::cin >> i;
    }
    std::sort(a.begin(), a.end());
    i128 ans = 1;
    for (auto i: a) {
        ans *= i;
        if (ans > 1000000000000000000) {
            std::cout << "-1\n";
            return;
        }
    }
    std::cout << (i64) ans << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr), std::cout.tie(nullptr);

    int T = 1;
    // std::cin >> T;
    while (T--) {
        solve();
    }

    return 0;
}