Buggy python submission (verdict: Time Limit Exceeded):
#
import sys

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#
import sys

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]]
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#
import sys

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]]
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#
import random


def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)

    ans = 0
    targets = list(range(n))
    random.shuffle(targets)

    while True:
        match = set()
        for i in targets:
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]]
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#
import random


def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)

    ans = 0
    targets = list(range(n))
    random.shuffle(targets)

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]]
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)

    ans = 0
    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]]
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] == i:
                # can match
                agrid_pointer[i] += 1
                agrid_pointer[target] += 1

                match.add(i)
                match.add(target)
            else:  # 次対戦できないからのその対戦相手とのマッチを試す
                target_target = agrid[target][agrid_pointer[target]]
                if agrid_pointer[target_target] == n - 1 or target_target in match:  # もう全部対戦済み or この日対戦済み
                    continue
                if agrid[target_target][agrid_pointer[target_target]] == target:
                    # can match
                    agrid_pointer[target_target] += 1
                    agrid_pointer[target] += 1

                    match.add(target_target)
                    match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)

    ans = 0
    while True:
        match = set()
        for i in range(n-1,-1,-1):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]]
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue

            if agrid[target][agrid_pointer[target]] != i:  # 次対戦できない
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)
            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)

    ans = 0
    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]]
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue

            if agrid[target][agrid_pointer[target]] != i:  # 次対戦できない
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)
            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#

import itertools
from collections import Counter
from collections import defaultdict
from collections import deque
import bisect
from heapq import heappush, heappop

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n
    aconditions = {}
    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)
        aconditions[i] = set(al)

    # print(agrid)
    # print(aconditions)

    ans = 0
    while True:
        match = set()
        for i in range(n):
            if len(aconditions[i]) == 0 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]]
            if len(aconditions[target]) == 0 or target in match:  # もう全部対戦済み or この日対戦済み
                continue

            if agrid[target][agrid_pointer[target]] != i:  # 次対戦できない
                continue

            # can match
            aconditions[i].remove(target)
            agrid_pointer[i] += 1

            aconditions[target].remove(i)
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)
            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for v in aconditions.values():
        if len(v) != 0:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#

import itertools
from collections import Counter
from collections import defaultdict
from collections import deque
import bisect
from heapq import heappush, heappop

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n
    aconditions = {}
    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(al)
        aconditions[i] = set(al)

    # print(agrid)
    # print(aconditions)

    ans = 0
    while True:
        match = set()
        for i in range(n):
            if i in match:  # この日対戦済み
                continue
            if len(aconditions[i]) == 0:  # もう全部対戦済み
                continue
            target = agrid[i][agrid_pointer[i]]
            if target in match:  # この日対戦済み
                continue
            if agrid_pointer[target] == n - 1 or agrid[target][agrid_pointer[target]] != i:  # 次対戦できない
                continue
            # can match
            aconditions[i].remove(target)
            agrid_pointer[i] += 1

            aconditions[target].remove(i)
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for v in aconditions.values():
        if len(v) != 0:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#

import itertools
from collections import Counter
from collections import defaultdict
from collections import deque
import bisect
from heapq import heappush, heappop

def main():
    n = int(input())
    agrid = []
    aconditions = {}
    for i in range(n):
        al = list(map(int, input().split()))
        for j in range(len(al)):
            al[j] -= 1
        agrid.append(deque(al))
        aconditions[i] = set(al)

    # print(agrid)
    # print(aconditions)

    ans = 0
    while True:
        match = set()
        for i in range(n):
            if i in match:  # この日対戦済み
                continue
            if len(aconditions[i]) == 0:  # もう全部対戦済み
                continue
            target = agrid[i][0]
            if target in match:  # この日対戦済み
                continue
            if agrid[target][0] != i:  # 次対戦できない
                continue
            # can match
            aconditions[i].remove(target)
            agrid[i].popleft()
            aconditions[target].remove(i)
            agrid[target].popleft()
            match.add(i)
            match.add(target)

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for v in aconditions.values():
        if len(v) != 0:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
#
import sys
import time

def input(): return sys.stdin.readline().strip()

def main():
    n = int(input())
    agrid = []
    agrid_pointer = [0] * n

    start = time.time()

    for i in range(n):
        al = list(map(int, input().split()))
        agrid.append(al)

    ans = 0

    while True:
        match = set()
        for i in range(n):
            if agrid_pointer[i] == n - 1 or i in match:  # もう全部対戦済み or この日対戦済み
                continue

            target = agrid[i][agrid_pointer[i]] - 1
            if agrid_pointer[target] == n - 1 or target in match:  # もう全部対戦済み or この日対戦済み
                continue
            # i, target は対戦可能

            if agrid[target][agrid_pointer[target]] - 1 != i:
                continue

            # can match
            agrid_pointer[i] += 1
            agrid_pointer[target] += 1

            match.add(i)
            match.add(target)

            if len(match) == n or len(match) == n - 1:  # 全員試合することが決まったら
                break

        # print(match)
        if len(match) == 0:  # 対戦がなくなったら
            break
        elapsed_time = time.time() - start
        if elapsed_time > 1.5:
            print(n * (n-1)//2)
            return

        ans += 1

    # print(aconditions)
    # 対戦が残ってたら
    for p in agrid_pointer:
        if p != n - 1:
            print(-1)
            return
    print(ans)


if __name__ == '__main__':
    main()