#include<stdio.h>
#include<stdlib.h>

#define OK 0
#define ERROR -1
#define MAXSIZE 1000

//定义队列
struct Queue{
	int front,rear; //队列头，尾下表
	int Q[MAXSIZE];
};
typedef struct Queue QUEUE;

//队列初始化
int init(QUEUE *q)
{
	q->front=q->rear=0;
	return OK;
}

//判断队列是否为空
int empty(QUEUE *q)
{
	if(q->rear==q->front)
		return OK;
	return ERROR;
}

//判断队列是否满
int full(QUEUE *q)
{
	return q->front==(q->rear+1)%MAXSIZE;
}

//入队操作
int push(QUEUE *q,int t)
{
	if(full(q))
		return ERROR;
	q->Q[q->rear]=t;
	q->rear=(q->rear+1)%MAXSIZE;
	return OK;
}

//出队操作
int pop(QUEUE *q)
{
	if(empty(q))
		return ERROR;
	q->front=(q->front+1)%MAXSIZE;
	return OK;
}

//返回队列的第一个元素
int gettop(QUEUE *q)
{
	return q->Q[q->front];
}

//计算队列排队需要的平均时间
int average(QUEUE *q)
{
	if(empty(q))
		return 0;
	else
	{
	 int sum,cnt;
	 sum=0;
	 cnt=0;
	 while(!empty(q))
	 {
		int t=gettop(q);
		cnt++;
		sum+=t;
		pop(q);
	 }
	 return sum/cnt;
	}
}


int main()
{
	int n,T;
	char X;
	QUEUE *qA,*qB,*qC;

	qA=(QUEUE*)malloc(sizeof(QUEUE));
	qB=(QUEUE*)malloc(sizeof(QUEUE));
	qC=(QUEUE*)malloc(sizeof(QUEUE));

	init(qA);
	init(qB);
	init(qC);

	scanf("%d",&n);
	while(n--)
	{
		getchar();
		scanf("%c%d",&X,&T);
		if(X=='A') push(qA,T);
		else if(X=='B') push(qB,T);
		else if(X=='C') push(qC,T);
		else printf("Do not serve such customers.");
	}
	printf("%d\n",average(qA));
	printf("%d\n",average(qB));
	printf("%d\n",average(qC));

	return 0;
}