import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];

		for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		}

		long prod = 1;
		for (int i = 0; i < n; i++) {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		}

		System.out.println(prod);

		sc.close();
	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];

		for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		}

		long prod = 1;
		for (int i = 0; i < n; i++) {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		}

		System.out.println(prod);

		sc.close();
	}

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];

		for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		}

		long prod = 1;
		for (int i = 0; i < n; i++) {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		}

		System.out.println(prod);

		sc.close();
	} main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];

		for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		}

		long prod = 1;
		for (int i = 0; i < n; i++) {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		}

		System.out.println(prod);

		sc.close();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc long a[] = new long[n]; a new long[n] n for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		} {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		} a[i] = sc.nextLong() a[i] a i sc.nextLong() sc.nextLong sc if (a[i] == 0) {
				System.out.println(0);
				return;
			} a[i] == 0 a[i] a i 0 {
				System.out.println(0);
				return;
			} System.out.println(0) System.out.println System.out System System.out 0 return; long prod = 1; prod 1 for (int i = 0; i < n; i++) {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		} {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		} if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			} 1000000000000000000l  / prod< a[i] 1000000000000000000l  / prod 1000000000000000000l prod a[i] a i {
				System.out.println(-1);
				return;
			} System.out.println(-1) System.out.println System.out System System.out -1 1 return; {
				prod *= a[i];
			} prod *= a[i] prod a[i] a i System.out.println(prod) System.out.println System.out System System.out prod sc.close() sc.close sc String[] args args public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];

		for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		}

		long prod = 1;
		for (int i = 0; i < n; i++) {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		}

		System.out.println(prod);

		sc.close();
	}

} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];

		for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		}

		long prod = 1;
		for (int i = 0; i < n; i++) {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		}

		System.out.println(prod);

		sc.close();
	}

} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];

		for (int i = 0; i < n; i++) {
			a[i] = sc.nextLong();
			if (a[i] == 0) {
				System.out.println(0);
				return;
			}
		}

		long prod = 1;
		for (int i = 0; i < n; i++) {
			if (1000000000000000000l  / prod< a[i]) {
				System.out.println(-1);
				return;
			} else {
				prod *= a[i];
			}
		}

		System.out.println(prod);

		sc.close();
	}

}
