import java.util.*;
import java.math.BigInteger;

public class Main {
  
  public static void main(String[] args) {
    
    Scanner scan = new Scanner(System.in);
    long N = scan.nextLong();
    long limit = (long) Math.pow(10,18);
    BigInteger product = new BigInteger("1");
    boolean smaller = true;
    
    for (int i = 1; i <= N; i++) {
      long A_i = scan.nextLong();
      
      if (A_i == 0) {
        System.out.println(0);
        return;
      }
      
      if (smaller) {
          product = product.multiply(BigInteger.valueOf(A_i));
      }
      
      if (smaller && product.compareTo(BigInteger.valueOf(limit)) == 1) {
        smaller = false;
      }  
    }
    
    if (smaller) {
      System.out.println(product);
    }
    
    else {
      System.out.println(-1);
    }
  }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz