import java.util.*;
import java.math.*;
import java.lang.*;

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;
      }
    }

    Arrays.sort(a);

    long ans = 1;

    for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    }

    System.out.println(ans);

  }

} import java.util.*; util.* java import java.math.*; math.* java import java.lang.*; lang.* java 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;
      }
    }

    Arrays.sort(a);

    long ans = 1;

    for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    }

    System.out.println(ans);

  }

} 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;
      }
    }

    Arrays.sort(a);

    long ans = 1;

    for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    }

    System.out.println(ans);

  } 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;
      }
    }

    Arrays.sort(a);

    long ans = 1;

    for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    }

    System.out.println(ans);

  } 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; Arrays.sort(a) Arrays.sort Arrays a long ans = 1; ans 1 for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    } {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    } if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      } ans > 1000000000000000000L/a[i] ans 1000000000000000000L/a[i] 1000000000000000000L a[i] a i {
        System.out.println(-1);
        return;
      } System.out.println(-1) System.out.println System.out System System.out -1 1 return; ans *= a[i] ans a[i] a i System.out.println(ans) System.out.println System.out System System.out ans 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;
      }
    }

    Arrays.sort(a);

    long ans = 1;

    for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    }

    System.out.println(ans);

  }

} 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;
      }
    }

    Arrays.sort(a);

    long ans = 1;

    for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    }

    System.out.println(ans);

  }

} Main
import java.util.*;
import java.math.*;
import java.lang.*;

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;
      }
    }

    Arrays.sort(a);

    long ans = 1;

    for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    }

    System.out.println(ans);

  }

}
