26 номера задач через одну

data = open('26_21719.txt').readlines()
n = int(data[0])
d = {}
for e in data[1:]:
    student, task = map(int, e.split())
    if student not in d:
        d[student] = []
    d[student].append(task)
mx = 0
best_student = -1
for student in d:
    d[student] = sorted(list(set(d[student])))
    answ = 0
    cur = 1
    for i in range(1, len(d[student])):
        if d[student][i] - d[student][i - 1] == 2:
            cur += 1
            answ = max(answ, cur)
        else:
            cur = 1
    if answ > mx:
        mx = answ
        best_student = student
print(best_student, mx)