소프티어

GBC 문제를 풀아보았는데, 결과는 잘나오는데 채점결과가 계속 0점입니다. ㅠ

도대체 뭐가 문제인지 모르겠어요, 도와주세요

import sys

try:

    n, m = input().split()

    #print(n)
    #print(m)

    arrayN = []

    for i in range(0,int(n)):
        x, y = input().split()
        arrayN.append([int(x),int(y)])
        
    #print (arrayN)



    arrayM = []

    for i in range(0,int(m)):
        x, y = input().split()
        arrayM.append([int(x),int(y)])    
        
    #print (arrayM)



    currentSectorN = 0
    currentSectorM = 0
    beforeN = 0
    beforeM = 0
    overSpeed = 0

    for i in range(1,100):
        
        if i > beforeN + arrayN[currentSectorN][0]:
            beforeN = i
            currentSectorN = currentSectorN +1 
        if i > beforeM + arrayM[currentSectorM][0]:
            beforeM = i
            currentSectorM = currentSectorM +1

        #print (i, currentSectorN,arrayN[currentSectorN][0], currentSectorM,arrayM[currentSectorM][0])

        if arrayN[currentSectorN][1] < arrayM[currentSectorM][1]:
            if overSpeed <  (arrayM[currentSectorM][1] - arrayN[currentSectorN][1]):
                overSpeed =  arrayM[currentSectorM][1] - arrayN[currentSectorN][1]

    
    print(overSpeed)
except:
    print ()