Buggy python submission (verdict: Time Limit Exceeded):
#!/usr/bin/env python3
import sys
import bisect

def iterate_tokens():
    for line in sys.stdin:
        for word in line.split():
            yield word

def solve(N: int):
    tokens = iterate_tokens()
    colors_top = []
    for i in range(N):
        new = int(next(tokens))
        if colors_top:
            b = bisect.bisect_left(colors_top, new)
            if b == 0:
                colors_top = [new] + colors_top
            else:
                colors_top[b-1] = new
        else:
            colors_top.append(new)
    print(len(colors_top))
    return


# Generated by 1.1.6 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    solve(N)

if __name__ == '__main__':
    main()


Fixed submission:
#!/usr/bin/env python3
import sys
import bisect

def iterate_tokens():
    for line in sys.stdin:
        for word in line.split():
            yield word

def solve(N: int):
    tokens = iterate_tokens()
    colors_top = []
    for i in range(N):
        new = int(next(tokens))
        if colors_top:
            b = bisect.bisect_right(colors_top, -new)
            if b == len(colors_top):
                colors_top.append(-new)
            else:
                colors_top[b] = -new
        else:
            colors_top.append(-new)
    print(len(colors_top))
    return


# Generated by 1.1.6 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    solve(N)

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import bisect

N = int(input())
now_top = -1
color = 1
prev_tops = []
for n in range(N):
    x = int(input())
    if x > now_top:
        now_top = x
    else:
        b = bisect.bisect_left(prev_tops, x)
        if b == 0:
            prev_tops.append(now_top)
            color += 1
            now_top = x
        else:
            b = b - 1
            push = now_top
            now_top = prev_tops[b]
            prev_tops = prev_tops[:b] + prev_tops[b+1:]
            prev_tops.append(push)
        prev_tops.sort()
print(color)


Fixed submission:
#!/usr/bin/env python3
import sys
import bisect

def iterate_tokens():
    for line in sys.stdin:
        for word in line.split():
            yield word

def solve(N: int):
    tokens = iterate_tokens()
    colors_top = []
    for i in range(N):
        new = int(next(tokens))
        if colors_top:
            b = bisect.bisect_right(colors_top, -new)
            if b == len(colors_top):
                colors_top.append(-new)
            else:
                colors_top[b] = -new
        else:
            colors_top.append(-new)
    print(len(colors_top))
    return


# Generated by 1.1.6 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    solve(N)

if __name__ == '__main__':
    main()