public static void main(String[] args) {
FScanner input = new FScanner();
out = new PrintWriter(new BufferedOutputStream(System.out), true);
int n = input.nextInt();
String specialString = "1";
long total = 0;
for (int i = 0; i < n; i++) {
String current = input.next();
char[] array = current.toCharArray();
if (array.length == 1 && array[0] == '0') {
out.println(0);
System.exit(0);
}
int countOne = 0;
int countZero = 0;
int countOthers = 0;
for (int j = 0; j < array.length; j++) {
if (array[j] == '1') {
countOne++;
} else if (array[j] == '0') {
countZero++;
} else {
countOthers++;
}
}
if (countOne > 1 || countOthers > 0) {
specialString = current;
} else {
total += countZero;
}
}
StringBuilder answer = new StringBuilder(specialString);
for (int i = 0; i < total; i++) {
answer = answer.append('0');
}
out.println(answer.toString());
out.close();
}
