Buggy python submission (verdict: Runtime Error):
N, W = map(int, input().split())

Ws = []
Vs = []

for _ in range(N):
  w, v = map(int, input().split())
  Ws.append(w)
  Vs.append(v)

Ans = [[0 for _ in range(N * max(Vs))+1] for _ in range(N)]

Ans[0][Vs[0]] = Ws[0]

for i in range(1, N):
  for v in range(N*max(Vs)+1):
    if v-Vs[i] >= 0:
      Ans[i][v] = max(Ans[i-1][v-Vs[i]] + Ws[i], Ans[i-1][v], Ans[i][v])
    else:
      Ans[i][v] = max(Ans[i-1][v], Ans[i][v])

AnsW = Ans[N-1]
AnsW.sorted()
for i in range(len(AnsW)-1):
  if AnsW[i+1] > W:
    print(AnsW[i])
    break

Fixed submission:
import sys
import pdb
input = sys.stdin.readline

N, W = map(int, input().split())
ws = [0]
vs = [0]

for _ in range(N):
  w, v = map(int, input().split())
  ws.append(w)
  vs.append(v)

inf = 2e11
V = int(sum(vs))   # N * max(vs)
# V = int(100 * 1e3)   # N * max(vs)
# Weight[i番目までの品番][価値j]
Weight = [[inf for _ in range(V+1)] for __ in range(N+1)]

if ws[1] <= W:
  Weight[1][vs[1]] = ws[1]
  value_max = vs[1]
else:
  value_max = 0

for _ in range(N+1):
  Weight[_][0] = 0

# pdb.set_trace()

for num in range(2, N+1):
  for value in range(1, V+1):
    if value >= vs[num]:   # 新しい品物を入れられるとき
      Weight[num][value] = min(Weight[num][value], Weight[num-1][value], Weight[num-1][value-vs[num]] + ws[num])
      if Weight[num][value] <= W:
        value_max = max(value_max, value)
      else:
        Weight[num][value] = inf
    else:   # 新しい品物を入れられないとき
      # 重さを変えることはできない
      Weight[num][value] = Weight[num-1][value]
      # Weight[num][value] = max(Weight[num][value], Weight[num-1][value])

# print(Weight)
print(value_max)

Buggy python submission (verdict: Runtime Error):
import sys
import pdb
input = sys.stdin.readline

N, W = map(int, input().split())
ws = [0]
vs = [0]

for _ in range(N):
  w, v = map(int, input().split())
  ws.append(w)
  vs.append(v)

inf = 2e11
V = int(sum(vs))   # N * max(vs)
# V = int(100 * 1e3)   # N * max(vs)
# Weight[i番目までの品番][価値j]
Weight = [[inf for _ in range(V+1)] for __ in range(N+1)]

if ws[1] <= W:
  Weight[1][vs[1]] = ws[1]
  value_max = vs[1]
else:
  value_max = 0

for _ in range(N+1):
  Weight[_][0] = 0

pdb.set_trace()

for num in range(2, N+1):
  for value in range(1, V+1):
    if value >= vs[num]:   # 新しい品物を入れられるとき
      Weight[num][value] = min(Weight[num][value], Weight[num-1][value], Weight[num-1][value-vs[num]] + ws[num])
      if Weight[num][value] <= W:
        value_max = max(value_max, value)
      else:
        Weight[num][value] = inf
    else:   # 新しい品物を入れられないとき
      # 重さを変えることはできない
      Weight[num][value] = Weight[num-1][value]
      # Weight[num][value] = max(Weight[num][value], Weight[num-1][value])

# print(Weight)
print(value_max)


Fixed submission:
import sys
import pdb
input = sys.stdin.readline

N, W = map(int, input().split())
ws = [0]
vs = [0]

for _ in range(N):
  w, v = map(int, input().split())
  ws.append(w)
  vs.append(v)

inf = 2e11
V = int(sum(vs))   # N * max(vs)
# V = int(100 * 1e3)   # N * max(vs)
# Weight[i番目までの品番][価値j]
Weight = [[inf for _ in range(V+1)] for __ in range(N+1)]

if ws[1] <= W:
  Weight[1][vs[1]] = ws[1]
  value_max = vs[1]
else:
  value_max = 0

for _ in range(N+1):
  Weight[_][0] = 0

# pdb.set_trace()

for num in range(2, N+1):
  for value in range(1, V+1):
    if value >= vs[num]:   # 新しい品物を入れられるとき
      Weight[num][value] = min(Weight[num][value], Weight[num-1][value], Weight[num-1][value-vs[num]] + ws[num])
      if Weight[num][value] <= W:
        value_max = max(value_max, value)
      else:
        Weight[num][value] = inf
    else:   # 新しい品物を入れられないとき
      # 重さを変えることはできない
      Weight[num][value] = Weight[num-1][value]
      # Weight[num][value] = max(Weight[num][value], Weight[num-1][value])

# print(Weight)
print(value_max)