1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
from collections import defaultdict
n, k = map(int, input().split())
last_color = defaultdict(int)
prev_h = 0
score = [ 0 ]
best = [ 0 ]
ofs = 0 
for i in range(1, n + 1):
    h, c = map(int, input().split())
    if h == prev_h:
        ofs += 1
    else:
        ofs = 0
    prev_h = h
    prev = i - 1 - ofs

    keep_color = score[last_color[c]] + h
    switch_color = best[prev] + h - k
    # duplicate box. should not really happen. just ignore this box / force color change.
    if last_color[c] > prev:
        keep_color = switch_color
    else:
        last_color[c] = i
    # best if we include this box
    score.append(max(keep_color, switch_color))
    # best for this color
    # best for all colors until this point
    best.append(max(best[-1], score[-1]))
print(best[-1])