Roller coaster

import sys
import string
import math

n = int(input())

tracks = []

for i in range (n):
    P, R, A, F = map(int, input().split())
    tracks.append((P, R, A, F, False))

tracks.reverse()
costs = [i[0] - i[1] for i in tracks]
costs.sort()
cost_index = len(costs) // 2
if len(costs) % 2 == 1:
    cost_index += 1

medianCost = costs[cost_index]
count = 0
for i in range (len(tracks)):
    if (tracks[i][0] - tracks[i][1] < cost_index and count < cost_index):
        count += 1
        tracks[i] = (tracks[i][0], tracks[i][1], tracks[i][2], tracks[i][3], True)

    print(tracks[i])

startingSpeed = 0
currentSpeed = 0
prevCost = 0
for i in range (len(tracks) - 1):
    currentCost = 0
    if tracks[i][4]:
        currentCost = tracks[i][0]
    else:
        currentCost = tracks[i][1]

    if (currentSpeed > currentCost):
        currentCost = currentSpeed
    unitsLost = tracks[i+1][2]
    percentageLost = tracks[i+1][3]

    currentSpeed = math.ceil(((currentCost + unitsLost) * 100) // (100 - percentageLost))
    print(math.ceil(currentSpeed))
    

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 20, in <module>
    medianCost = costs[cost_index]
IndexError: list index out of range

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER