import java.math.BigInteger;
import java.util.Scanner;
public class Fgh {

    public static void main(String[] args) {
        long  n,x,i;
        BigInteger f=new BigInteger("1");
        BigInteger l=new BigInteger("1000000000000000000");
        Scanner inpu=new Scanner(System.in);
        n=inpu.nextLong();
        for(i=0;i<n;i++) {
        x=inpu.nextLong();
        f=f.multiply(BigInteger.valueOf(x));

        }
        int val=f.compareTo(l);
        if(val==1)System.out.println("-1");
        else System.out.println(f);

    }

}