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];
		long sum = 1;
		boolean ch = false;
		long max = 1000000000000000000l;

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

		for(int i = 0; i < n; i++) {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		}
		System.out.println(sum);

	}

} 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];
		long sum = 1;
		boolean ch = false;
		long max = 1000000000000000000l;

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

		for(int i = 0; i < n; i++) {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		}
		System.out.println(sum);

	}

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];
		long sum = 1;
		boolean ch = false;
		long max = 1000000000000000000l;

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

		for(int i = 0; i < n; i++) {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		}
		System.out.println(sum);

	} main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];
		long sum = 1;
		boolean ch = false;
		long max = 1000000000000000000l;

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

		for(int i = 0; i < n; i++) {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		}
		System.out.println(sum);

	} 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 long sum = 1; sum 1 boolean ch = false; ch false long max = 1000000000000000000l; max 1000000000000000000l 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; for(int i = 0; i < n; i++) {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		} int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		} {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		} if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			} max/sum < a[i] max/sum max sum a[i] a i {
				System.out.println("-1");
				return;
			} System.out.println("-1") System.out.println System.out System System.out "-1" return; sum *= a[i] sum a[i] a i if(sum > max) {
				System.out.println("-1");
			} sum > max sum max {
				System.out.println("-1");
			} System.out.println("-1") System.out.println System.out System System.out "-1" System.out.println(sum) System.out.println System.out System System.out sum 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];
		long sum = 1;
		boolean ch = false;
		long max = 1000000000000000000l;

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

		for(int i = 0; i < n; i++) {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		}
		System.out.println(sum);

	}

} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long a[] = new long[n];
		long sum = 1;
		boolean ch = false;
		long max = 1000000000000000000l;

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

		for(int i = 0; i < n; i++) {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		}
		System.out.println(sum);

	}

} 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];
		long sum = 1;
		boolean ch = false;
		long max = 1000000000000000000l;

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

		for(int i = 0; i < n; i++) {
			if(max/sum < a[i]) {
				System.out.println("-1");
				return;
			}
			sum *= a[i];
			if(sum > max) {
				System.out.println("-1");
			}

		}
		System.out.println(sum);

	}

}
