Buggy python submission (verdict: Time Limit Exceeded):
import collections,sys
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
N,W = LI()
wv = [LI() for _ in range(N)]
dp = [collections.defaultdict(int) for _ in range(N+1)] #1_indexed
dp[0][0] = 0
for i in range(1,N+1):
    w,v = wv[i-1]
    for dw,dv in dp[i-1].items():
        dp[i][dw] = max(dp[i][dw],dv)
        if dw+w<=W:
            dp[i][dw+w] = max(dp[i][dw+w],dv+v)
print(max(dp[-1].values()))


Fixed submission:
import itertools,sys
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
N,W = LI()
wv = [LI() for _ in range(N)]
dp = [[0]*(W+1) for _ in range(N+1)] #1_indexed
for i,j in itertools.product(range(N),range(W+1)):
    w,v = wv[i]
    if j-w>=0:
        dp[i+1][j] = max(dp[i+1][j],dp[i][j-w]+v)
    dp[i+1][j] = max(dp[i+1][j],dp[i][j])
print(dp[-1][-1])

Buggy python submission (verdict: Time Limit Exceeded):
import collections,sys
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
N,W = LI()
wv = [LI() for _ in range(N)]
dp = [collections.defaultdict(int) for _ in range(N+1)] #1_indexed
dp[0][0] = 0
for i in range(1,N+1):
    w,v = wv[i-1]
    for dw,dv in dp[i-1].items():
        dp[i][dw] = max(dp[i][dw],dv)
        if w+dw<=W:
            dp[i][w+dw] = max(dp[i][w+dw],v+dv)
print(max(dp[-1].values()))


Fixed submission:
import itertools,sys
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
N,W = LI()
wv = [LI() for _ in range(N)]
dp = [[0]*(W+1) for _ in range(N+1)] #1_indexed
for i,j in itertools.product(range(N),range(W+1)):
    w,v = wv[i]
    if j-w>=0:
        dp[i+1][j] = max(dp[i+1][j],dp[i][j-w]+v)
    dp[i+1][j] = max(dp[i+1][j],dp[i][j])
print(dp[-1][-1])

Buggy python submission (verdict: Time Limit Exceeded):
import itertools,sys
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
N,W = LI()
wv = [LI() for _ in range(N)]
dp = [[0]*(W+1) for _ in range(N+1)] #1_indexed
for i,j in itertools.product(range(1,N+1),range(W+1)):
    w,v = wv[i-1]
    if j-w>=0:
        dp[i][j] = max(dp[i][j],dp[i-1][j-w]+v)
    dp[i][j] = max(dp[i][j],dp[i-1][j])
print(dp[-1][-1])


Fixed submission:
import itertools,sys
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
N,W = LI()
wv = [LI() for _ in range(N)]
dp = [[0]*(W+1) for _ in range(N+1)] #1_indexed
for i,j in itertools.product(range(N),range(W+1)):
    w,v = wv[i]
    if j-w>=0:
        dp[i+1][j] = max(dp[i+1][j],dp[i][j-w]+v)
    dp[i+1][j] = max(dp[i+1][j],dp[i][j])
print(dp[-1][-1])

Buggy python submission (verdict: Time Limit Exceeded):
import itertools,sys
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
N,W = LI()
wv = [LI() for _ in range(N)]
dp = [[0]*(W+1) for _ in range(N+1)] #1_indexed
for i,j in itertools.product(range(N),range(W+1)):
    w,v = wv[i]
    if j-w>=0:
        dp[i+1][j] = max(dp[i+1][j],dp[i][j-w]+v)
    dp[i+1][j] = max(dp[i+1][j],dp[i][j])
print(dp[-1][-1])


Fixed submission:
import itertools,sys
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
N,W = LI()
wv = [LI() for _ in range(N)]
dp = [[0]*(W+1) for _ in range(N+1)] #1_indexed
for i,j in itertools.product(range(N),range(W+1)):
    w,v = wv[i]
    if j-w>=0:
        dp[i+1][j] = max(dp[i+1][j],dp[i][j-w]+v)
    dp[i+1][j] = max(dp[i+1][j],dp[i][j])
print(dp[-1][-1])