import java.io.IOException;
import java.math.BigInteger;

public class Main {
    private static final StringBuilder builder = new StringBuilder();
    public static void main(String[] args) {
        int n = readInt();
        BigInteger bi = BigInteger.ONE;
        BigInteger comp = new BigInteger("1000000000000000000");
        boolean over = false;

        for (int i = 0; i < n; i++) {
            long a = readLong();
            if (a == 0) {
                System.out.print(0);
                return;
            }
            
            if (over) {
                continue;
            }
            
            bi = bi.multiply(BigInteger.valueOf(a));
            if (bi.compareTo(comp) > 0) {
                over = true;
            }
        }
        
        String ans = over ? "-1" : bi.toString();

        System.out.print(ans);
    }

    private static void read() {
        builder.setLength(0);
        while (true) {
            try {
                int b = System.in.read();
                if (b == ' ' || b == '\n' || b == -1) {
                    break;
                } else {
                    builder.appendCodePoint(b);
                }
            } catch (IOException e) {
                break;
            }
        }
    }

    private static int readInt() {
        read();
        return Integer.parseInt(builder.toString());
    }

    private static int readInt(int radix) {
        read();
        return Integer.parseInt(builder.toString(), radix);
    }

    private static long readLong() {
        read();
        return Long.parseLong(builder.toString());
    }

    private static long readLong(int radix) {
        read();
        return Long.parseLong(builder.toString(), radix);
    }

    private static BigInteger readBigInteger() {
        read();
        return new BigInteger(builder.toString());
    }

    private static BigInteger readBigInteger(int radix) {
        read();
        return new BigInteger(builder.toString(), radix);
    }

    private static void skipLine() {
        while (true) {
            try {
                int b = System.in.read();
                if (b == '\n' || b == -1) {
                    break;
                }
            } catch (IOException e) {
                break;
            }
        }
    }

    private static void skip() {
        while (true) {
            try {
                int b = System.in.read();
                if (b == ' ' || b == '\n' || b == -1) break;
            } catch (IOException e) {
                break;
            }
        }
    }

}

/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