Buggy python submission (verdict: Runtime Error):
N, M, K = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
ab_sum , answer, b_i = sum(B), 0, M
for a_i in range(N+1):
  while b_i>0 and ab_sum >K:
    b_i -= 1
    ab_sum -= B[b_i]
  if ab_sum >K:
    break
  answer = max(answer, a_i+b_i)
  ab_sum += A[a_i]

print(answer)


Fixed submission:
N, M, K = map(int, input().split())
a_books = list(map(int, input().split()))
b_books = list(map(int, input().split()))
a_time = 0
b_time = 0
a_times = [0 for _ in range(N+1)]
b_times = [0 for _ in range(M+1)]
for i, a in enumerate(a_books):
  a_time += a
  a_times[i+1] = a_time
  
for i, b in enumerate(b_books):
  b_time += b
  b_times[i+1] = b_time
  
result = 0
l = 0
for i in range(N+1):
  if l == M:
    break
  while(l <= M):
    if a_times[N-i] + b_times[l] <= K:
      result = max(result, N-i+l)
      l += 1
    else:
      break
print(result)

Buggy python submission (verdict: Runtime Error):
N, M, K = map(int, input().split())
a_books = list(map(int, input().split()))
b_books = list(map(int, input().split()))
a_time = 0
b_time = 0
a_times = [0 for _ in range(N+1)]
b_times = [0 for _ in range(M+1)]
for i, a in enumerate(a_books):
  a_time += a
  a_times[i+1] = a_time
  
for i, b in enumerate(b_books):
  b_time += b
  b_times[i+1] = b_time
  
result = 0
l = 0
for i in range(N+1):
  if l == M:
    break
  while(True):
    if a_times[N-i] + b_times[l] <= K:
      result = max(result, N-i+l)
      l += 1
    else:
      break
print(result)

Fixed submission:
N, M, K = map(int, input().split())
a_books = list(map(int, input().split()))
b_books = list(map(int, input().split()))
a_time = 0
b_time = 0
a_times = [0 for _ in range(N+1)]
b_times = [0 for _ in range(M+1)]
for i, a in enumerate(a_books):
  a_time += a
  a_times[i+1] = a_time
  
for i, b in enumerate(b_books):
  b_time += b
  b_times[i+1] = b_time
  
result = 0
l = 0
for i in range(N+1):
  if l == M:
    break
  while(l <= M):
    if a_times[N-i] + b_times[l] <= K:
      result = max(result, N-i+l)
      l += 1
    else:
      break
print(result)

Buggy python submission (verdict: Time Limit Exceeded):
N, M, K = map(int, input().split())
a_books = list(map(int, input().split()))
b_books = list(map(int, input().split()))
a_time = 0
b_time = 0
a_times = [0 for _ in range(N+1)]
b_times = [0 for _ in range(M+1)]
for i, a in enumerate(a_books):
  a_time += a
  a_times[i+1] = a_time
  
for i, b in enumerate(b_books):
  b_time += b
  b_times[i+1] = b_time
  
result = 0
l = 0
for i in range(N+1):
  if l == M:
    break
  for j in range(l, M+1):
    if a_times[N-i] + b_times[j] <= K:
      result = max(result, N-i+j)
    else:
      l = j
      break
print(result)

Fixed submission:
N, M, K = map(int, input().split())
a_books = list(map(int, input().split()))
b_books = list(map(int, input().split()))
a_time = 0
b_time = 0
a_times = [0 for _ in range(N+1)]
b_times = [0 for _ in range(M+1)]
for i, a in enumerate(a_books):
  a_time += a
  a_times[i+1] = a_time
  
for i, b in enumerate(b_books):
  b_time += b
  b_times[i+1] = b_time
  
result = 0
l = 0
for i in range(N+1):
  if l == M:
    break
  while(l <= M):
    if a_times[N-i] + b_times[l] <= K:
      result = max(result, N-i+l)
      l += 1
    else:
      break
print(result)

Buggy python submission (verdict: Time Limit Exceeded):
N, M, K = map(int, input().split())
a_books = list(map(int, input().split()))
b_books = list(map(int, input().split()))
a_time = 0
b_time = 0
a_times = [0 for _ in range(N+1)]
b_times = [0 for _ in range(M+1)]
for i, a in enumerate(a_books):
  a_time += a
  a_times[i+1] = a_time
  
for i, b in enumerate(b_books):
  b_time += b
  b_times[i+1] = b_time
  
result = 0
l = 0
for i in range(N+1):
  for j in range(l, M+1):
    if a_times[N-i] + b_times[j] <= K:
      result = max(result, N-i+j)
    else:
      l = j
      break
print(result)

Fixed submission:
N, M, K = map(int, input().split())
a_books = list(map(int, input().split()))
b_books = list(map(int, input().split()))
a_time = 0
b_time = 0
a_times = [0 for _ in range(N+1)]
b_times = [0 for _ in range(M+1)]
for i, a in enumerate(a_books):
  a_time += a
  a_times[i+1] = a_time
  
for i, b in enumerate(b_books):
  b_time += b
  b_times[i+1] = b_time
  
result = 0
l = 0
for i in range(N+1):
  if l == M:
    break
  while(l <= M):
    if a_times[N-i] + b_times[l] <= K:
      result = max(result, N-i+l)
      l += 1
    else:
      break
print(result)