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()))

Sa = [0]*N
Sb = [0]*M
Sa[0] = A[0]
Sb[0] = B[0]
a = 0
b = 0
if Sa[0] > K:
    a = 0
else: 
    for i in range(1, N):
        Sa[i] = Sa[i-1] + A[i]
        if Sa[i] > K:
            a = i
            break
    else:
        a = N
if Sb[0] > K:
    b = 0
else:
    for i in range(1, M):
        Sb[i] = Sb[i-1] + B[i]
        if Sb[i] > K:
            b = i
            break
    else:
        b = M

ans = max(a, b)
for i in range(a):
    temp = K - Sa[i]
    if i+1+b =< ans:
        break
    for j in range(b):
        if Sb[j] > temp:
            ans = max(ans, i+1+j)
            break
    else:
        ans = max(ans, i+1+b)
print(ans)


Fixed submission:
N, M ,K = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

Sa = [0]*(N+1)
Sb = [0]*(M+1)
Sa[0] = 0
Sb[0] = 0
for i in range(N):
    Sa[i+1] = Sa[i] + A[i]
for i in range(M):
    Sb[i+1] = Sb[i] + B[i]
ans = 0
for i in range(N+1):
    if Sa[i] > K:
        break
    for j in range(M, -1, -1):
        if Sa[i]+Sb[j] <= K:
            ans = max(ans, i+j)
            M = j
            break
    else:
        ans = max(ans, i)
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
N, M ,K = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

Sa = [0]*N
Sb = [0]*M
Sa[0] = A[0]
Sb[0] = B[0]
a = 0
b = 0
if Sa[0] > K:
    a = 0
else: 
    for i in range(1, N):
        Sa[i] = Sa[i-1] + A[i]
        if Sa[i] > K:
            a = i
            break
    else:
        a = N
if Sb[0] > K:
    b = 0
else:
    for i in range(1, M):
        Sb[i] = Sb[i-1] + B[i]
        if Sb[i] > K:
            b = i
            break
    else:
        b = M

ans = max(a, b)
for i in range(a):
    temp = K - Sa[i]
    for j in range(b):
        if Sb[j] > temp:
            ans = max(ans, i+1+j)
            break
    else:
        ans = max(ans, i+1+b)
print(ans)


Fixed submission:
N, M ,K = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

Sa = [0]*(N+1)
Sb = [0]*(M+1)
Sa[0] = 0
Sb[0] = 0
for i in range(N):
    Sa[i+1] = Sa[i] + A[i]
for i in range(M):
    Sb[i+1] = Sb[i] + B[i]
ans = 0
for i in range(N+1):
    if Sa[i] > K:
        break
    for j in range(M, -1, -1):
        if Sa[i]+Sb[j] <= K:
            ans = max(ans, i+j)
            M = j
            break
    else:
        ans = max(ans, i)
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
N, M ,K = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

Sa = [0]*N
Sb = [0]*M
Sa[0] = A[0]
Sb[0] = B[0]
a = 0
b = 0
if Sa[0] > K:
    a = 0
else: 
    for i in range(1, N):
        Sa[i] = Sa[i-1] + A[i]
        if Sa[i] > K:
            a = i
            break
    else:
        a = N
if Sb[0] > K:
    b = 0
else:
    for i in range(1, M):
        Sb[i] = Sb[i-1] + B[i]
        if Sb[i] > K:
            b = i
            break
    else:
        b = M

ans = max(a, b)
for i in range(a):
    temp = K - Sa[i]
    for j in range(b):
        if Sb[j] > temp:
            ans = max(ans, i+1+j)
            break
    else:
        ans = max(ans, i+1+b)
print(ans)


Fixed submission:
N, M ,K = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

Sa = [0]*(N+1)
Sb = [0]*(M+1)
Sa[0] = 0
Sb[0] = 0
for i in range(N):
    Sa[i+1] = Sa[i] + A[i]
for i in range(M):
    Sb[i+1] = Sb[i] + B[i]
ans = 0
for i in range(N+1):
    if Sa[i] > K:
        break
    for j in range(M, -1, -1):
        if Sa[i]+Sb[j] <= K:
            ans = max(ans, i+j)
            M = j
            break
    else:
        ans = max(ans, i)
print(ans)