Buggy python submission (verdict: Time Limit Exceeded):
from itertools import product

N, A = map(int, input().split())
x = [int(x) for x in input().split()]

max_x = max(max(x), A)
dp = [[[0 for _ in range((N + 1) * max_x)] for _ in range(N + 1)] for _ in range(N + 1)]
dp[0][0][0] = 1

for j, k, s in product(range(1, N + 1), range(N + 1), range((N + 1) * max_x)):
    if s < x[j - 1]:
        dp[j][k][s] = dp[j - 1][k][s]
    elif k >= 1 and s >= x[j - 1]:
        dp[j][k][s] = dp[j - 1][k][s] + dp[j - 1][k - 1][s - x[j - 1]]

ans = 0
for k in range(1, N + 1):
    ans += dp[N][k][k * A]
print(ans)

Fixed submission:
from itertools import product

N, A = map(int, input().split())
x = [int(x) for x in input().split()]

X = max(max(x), A)
dp = [[0 for _ in range(2 * N * X + 1)] for _ in range(N + 1)]
dp[0][N * X] = 1

for j, t in product(range(1, N + 1), range(2 * N * X + 1)):
    y = x[j - 1] - A
    if t - y < 0 or t - y > 2 * N * X:
        dp[j][t] = dp[j - 1][t]
    elif 0 <= t - y <= 2 * N * X:
        dp[j][t] = dp[j - 1][t] + dp[j - 1][t - y]
print(dp[N][N * X] - 1)

Buggy python submission (verdict: Runtime Error):
from itertools import product

N, A = map(int, input().split())
x = [int(x) for x in input().split()]

max_x = max(max(x), A)
dp = [[[0 for _ in range(N * max_x)] for _ in range(N + 1)] for _ in range(N + 1)]
dp[0][0][0] = 1

for j, k, s in product(range(1, N + 1), range(N + 1), range(N * max_x)):
    if s < x[j - 1]:
        dp[j][k][s] = dp[j - 1][k][s]
    elif k >= 1 and s >= x[j - 1]:
        dp[j][k][s] = dp[j - 1][k][s] + dp[j - 1][k - 1][s - x[j - 1]]

ans = 0
for k in range(1, N + 1):
    ans += dp[N][k][k * A]
print(ans)


Fixed submission:
from itertools import product

N, A = map(int, input().split())
x = [int(x) for x in input().split()]

X = max(max(x), A)
dp = [[0 for _ in range(2 * N * X + 1)] for _ in range(N + 1)]
dp[0][N * X] = 1

for j, t in product(range(1, N + 1), range(2 * N * X + 1)):
    y = x[j - 1] - A
    if t - y < 0 or t - y > 2 * N * X:
        dp[j][t] = dp[j - 1][t]
    elif 0 <= t - y <= 2 * N * X:
        dp[j][t] = dp[j - 1][t] + dp[j - 1][t - y]
print(dp[N][N * X] - 1)

Buggy python submission (verdict: Runtime Error):
N, A = map(int, input().split())
x = [int(x) for x in input().split()]

max_x = max(x)
dp = [[[0 for _ in range((N + 1) * max_x)] for _ in range(N + 1)] for _ in range(N + 1)]
dp[0][0][0] = 1

for j in range(1, N + 1):
    for k in range(N + 1):
        for s in range((N + 1) * max_x):
            if s < x[j - 1]:
                dp[j][k][s] = dp[j - 1][k][s]
            elif k >= 1 and s >= x[j - 1]:
                dp[j][k][s] = dp[j - 1][k][s] + dp[j - 1][k - 1][s - x[j - 1]]

ans = 0
for k in range(1, N + 1):
    ans += dp[N][k][k * A]
print(ans)


Fixed submission:
from itertools import product

N, A = map(int, input().split())
x = [int(x) for x in input().split()]

X = max(max(x), A)
dp = [[0 for _ in range(2 * N * X + 1)] for _ in range(N + 1)]
dp[0][N * X] = 1

for j, t in product(range(1, N + 1), range(2 * N * X + 1)):
    y = x[j - 1] - A
    if t - y < 0 or t - y > 2 * N * X:
        dp[j][t] = dp[j - 1][t]
    elif 0 <= t - y <= 2 * N * X:
        dp[j][t] = dp[j - 1][t] + dp[j - 1][t - y]
print(dp[N][N * X] - 1)