import java.util.Scanner;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    long acum = 1;
    boolean cs = false;
    for(int i = 0; i < n; i++) {
      try {
        acum = Math.multiplyExact(acum, sc.nextLong());      
      } catch(ArithmeticException e) {
        cs = true;
      }
    }
    sc.close();
    if(acum != 0 && (acum > 1000000000000000000L || cs)) {
      System.out.println("-1");
    } else {
      System.out.println(acum);
    }
  }
}
/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