import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		try(Scanner sc = new Scanner(System.in)) {

			//			long a = Long.MAX_VALUE + 1;
			long max = (long)Math.pow(10, 18);

			//			System.out.println(a);
			//			System.out.println(max+1);


			int n = sc.nextInt();

			long ans = 1;
			boolean isOver = false;
			for(int i = 0 ; i < n ; i++ ) {
				long ai = sc.nextLong();

				if ( ai == 0 ) {
					System.out.println("0");
					return;
				}

				if ( !isOver ) {
					try {
						ans = Math.multiplyExact(ans, ai);
					}
					catch(Exception e) {
						isOver = true;
					}
				}

				if ( ans > max || ans < 0 ) {
					isOver = true;
				}
			}

			if ( isOver ) {
				System.out.println("-1");
			}
			else {
				System.out.println(ans);
			}

		}
	}

}
/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