Buggy python submission (verdict: Runtime Error):
N, W = list(map(int, input().split()))
WE = []
V = []
for i in range(N):
    w, v = list(map(int, input().split()))
    WE.append(w)
    V.append(v)

# MAX_W = 10 ** 5
MAX_W = 10 ** 9

# DP[i][j]: i以降の品物で重さj以下のときの価値の最大
DP = []
for i in range(N):
    a = [None] * (MAX_W + 1)
    DP.append(a)
DP.append([0] * (MAX_W+1))

for i in range(N-1, -1, -1):
    for j in range(MAX_W+1):
        if i == N:  # i番目の品物はない
            DP[i][j] == 0
        elif j < WE[i]:  # この重さの品物は入れないから無視
            DP[i][j] = DP[i+1][j]
        else:
            DP[i][j] = max(DP[i+1][j], DP[i+1][j-WE[i]]+V[i])

# for i in range(N):
#     print(DP[i][:10])
print(DP[0][W])

Fixed submission:
N, W = list(map(int, input().split()))
WE = []
V = []
INF = float('inf')
for i in range(N):
    w, v = list(map(int, input().split()))
    WE.append(w)
    V.append(v)

MAX_V = (10 ** 3) * 100 + 1

# DP[i+1][j]: i番目までの品物から価値の総和がjとなるように選んだときの、重さの総和の最小値
DP = []
for i in range(N+1):
    a = [INF] * (MAX_V + 1)
    DP.append(a)

DP[0][0] = 0

for i in range(N):
    for j in range(MAX_V):
        if j < V[i]:  # 作りたい価値の総和よりも、価値が大きい
            DP[i+1][j] = DP[i][j]
        else:
            DP[i+1][j] = min(DP[i][j], DP[i][j-V[i]] + WE[i])

r = 0
for i in range(MAX_V+1):
    if DP[N][i] <= W:
        r = i

print(r)

# for i in range(N+1):
    # print(DP[i][:20])

Buggy python submission (verdict: Runtime Error):
N, W = list(map(int, input().split()))
WE = []
V = []
for i in range(N):
    w, v = list(map(int, input().split()))
    WE.append(w)
    V.append(v)

# MAX_W = 10 ** 5
MAX_W = 10 ** ９

# DP[i][j]: i以降の品物で重さj以下のときの価値の最大
DP = []
for i in range(N):
    a = [None] * (MAX_W + 1)
    DP.append(a)
DP.append([0] * (MAX_W+1))

for i in range(N-1, -1, -1):
    for j in range(MAX_W+1):
        if i == N:  # i番目の品物はない
            DP[i][j] == 0
        elif j < WE[i]:  # この重さの品物は入れないから無視
            DP[i][j] = DP[i+1][j]
        else:
            DP[i][j] = max(DP[i+1][j], DP[i+1][j-WE[i]]+V[i])

# for i in range(N):
#     print(DP[i][:10])
print(DP[0][W])

Fixed submission:
N, W = list(map(int, input().split()))
WE = []
V = []
INF = float('inf')
for i in range(N):
    w, v = list(map(int, input().split()))
    WE.append(w)
    V.append(v)

MAX_V = (10 ** 3) * 100 + 1

# DP[i+1][j]: i番目までの品物から価値の総和がjとなるように選んだときの、重さの総和の最小値
DP = []
for i in range(N+1):
    a = [INF] * (MAX_V + 1)
    DP.append(a)

DP[0][0] = 0

for i in range(N):
    for j in range(MAX_V):
        if j < V[i]:  # 作りたい価値の総和よりも、価値が大きい
            DP[i+1][j] = DP[i][j]
        else:
            DP[i+1][j] = min(DP[i][j], DP[i][j-V[i]] + WE[i])

r = 0
for i in range(MAX_V+1):
    if DP[N][i] <= W:
        r = i

print(r)

# for i in range(N+1):
    # print(DP[i][:20])

Buggy python submission (verdict: Runtime Error):
N, W = list(map(int, input().split()))
WE = []
V = []
for i in range(N):
    w, v = list(map(int, input().split()))
    WE.append(w)
    V.append(v)

MAX_W = 10 ** 5

# DP[i][j]: i以降の品物で重さj以下のときの価値の最大
DP = []
for i in range(N):
    a = [None] * (MAX_W + 1)
    DP.append(a)
DP.append([0] * (MAX_W+1))

for i in range(N-1, -1, -1):
    for j in range(MAX_W+1):
        if i == N:  # i番目の品物はない
            DP[i][j] == 0
        elif j < WE[i]:  # この重さの品物は入れないから無視
            DP[i][j] = DP[i+1][j]
        else:
            DP[i][j] = max(DP[i+1][j], DP[i+1][j-WE[i]]+V[i])

# for i in range(N):
#     print(DP[i][:10])
print(DP[0][W])

Fixed submission:
N, W = list(map(int, input().split()))
WE = []
V = []
INF = float('inf')
for i in range(N):
    w, v = list(map(int, input().split()))
    WE.append(w)
    V.append(v)

MAX_V = (10 ** 3) * 100 + 1

# DP[i+1][j]: i番目までの品物から価値の総和がjとなるように選んだときの、重さの総和の最小値
DP = []
for i in range(N+1):
    a = [INF] * (MAX_V + 1)
    DP.append(a)

DP[0][0] = 0

for i in range(N):
    for j in range(MAX_V):
        if j < V[i]:  # 作りたい価値の総和よりも、価値が大きい
            DP[i+1][j] = DP[i][j]
        else:
            DP[i+1][j] = min(DP[i][j], DP[i][j-V[i]] + WE[i])

r = 0
for i in range(MAX_V+1):
    if DP[N][i] <= W:
        r = i

print(r)

# for i in range(N+1):
    # print(DP[i][:20])