void addNumber(int number): Add number to the data structure.

void removeFirstAddedNumber(): Remove the earliest added number from the data structure.

int getMean(): Return the floored mean of the numbers in the data structure.

int getMedian(): Return the median of the numbers in the data structure.

int getMode(): Return the mode of the numbers in the data structure. If there are multiple modes, return the smallest one.

Note:

The mean of an array is the sum of all the values divided by the number of values in the array.
The median of an array is the middle element of the array when it is sorted in non-decreasing order. If there are two choices for a median, the larger of the two values is taken.
The mode of an array is the element that appears most often in the array.

Input:
["StatisticsTracker", "addNumber", "addNumber", "addNumber", "addNumber", "getMean", "getMedian", "getMode", "removeFirstAddedNumber"