Descr iption

本题题意对于书上内容有变动，“设车辆到达服从均匀分布，参数由用户指定”改为“输入数据给出每辆车的到达时间”。



Input Format

第一行含有一个正整数N（1<=N<=20000),代表总车辆数。



第二行到第N+1行，每行包含两个整数p,q.（0<=p<=1,0<=q<=100000）。p代表车辆类型，0代表客车，1代表货车。q代表到达时间（单位为分钟）。



Output Format

输出包含两个数a，b。代表客车和货车的平均等待时间，精确到小数点后三位。-Descr iption of the meaning of the title for the book title contents are subject to change, " set the vehicle arrives uniformly distributed, the parameters specified by the user"　to " input data given vehicle arrival time."　Input Format The first line contains a positive integer N (1 < = N < = 20000), represents the total number of vehicles. N+1 second line to the first line, each line contains two integers p, q. (0 < = p < = 1,0 < = q < = 100000). p represents a vehicle type, 0 bus, 1 van. q represents the arrival time (in minutes). Output Format The output contains two numbers a, b. The average wait time on behalf of buses and trucks, accurate to three decimal places.