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

S_ba = []
S_ab = []
for i in range(N):
    if A[i] < B[i]: S_ba.append(B[i] - A[i])
    elif A[i] > B[i]: S_ab.append(A[i] - B[i])

if sum(S_ba) > sum(S_ab):
    print(-1)
    exit()
    
ans = len(S_ba)
now = 0
S_ab.sort(reverse=True)
for i in range(len(S_ab)):
    if sum(S_ba) <= now: break
    now += S_ab[i]
    ans += 1

print(ans)


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

S_ba = []
S_ab = []
for i in range(N):
    if A[i] < B[i]: S_ba.append(B[i] - A[i])
    elif A[i] > B[i]: S_ab.append(A[i] - B[i])

if sum(S_ba) > sum(S_ab):
    print(-1)
    exit()
    
ans = len(S_ba)
now = 0
rem = sum(S_ba)
S_ab.sort(reverse=True)
for i in range(len(S_ab)):
    if rem <= now: break
    now += S_ab[i]
    ans += 1

print(ans)

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

S_ba = []
S_ab = []
for i in range(N):
    if A[i] < B[i]: S_ba.append(B[i] - A[i])
    else: S_ab.append(A[i] - B[i])

if sum(S_ba) > sum(S_ab):
    print(-1)
    exit()
    
ans = len(S_ba)
now = 0
S_ab.sort(reverse=True)
for i in range(len(S_ab)):
    # now += A[i] - B[i]
    if sum(S_ba) <= now: break
    now += S_ab[i]
    ans += 1

print(ans)

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

S_ba = []
S_ab = []
for i in range(N):
    if A[i] < B[i]: S_ba.append(B[i] - A[i])
    elif A[i] > B[i]: S_ab.append(A[i] - B[i])

if sum(S_ba) > sum(S_ab):
    print(-1)
    exit()
    
ans = len(S_ba)
now = 0
rem = sum(S_ba)
S_ab.sort(reverse=True)
for i in range(len(S_ab)):
    if rem <= now: break
    now += S_ab[i]
    ans += 1

print(ans)

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

S_ba = []
S_ab = []
for i in range(N):
    if A[i] < B[i]: S_ba.append(B[i] - A[i])
    else: S_ab.append(A[i] - B[i])

if sum(S_ba) > sum(S_ab):
    print(-1)
    exit()
    
ans = len(S_ba)
now = 0
S_ab.sort(reverse=True)
for i in range(len(S_ab)):
    # now += A[i] - B[i]
    if sum(S_ba) <= now: break
    now += S_ab[i]
    ans += 1

print(ans)


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

S_ba = []
S_ab = []
for i in range(N):
    if A[i] < B[i]: S_ba.append(B[i] - A[i])
    elif A[i] > B[i]: S_ab.append(A[i] - B[i])

if sum(S_ba) > sum(S_ab):
    print(-1)
    exit()
    
ans = len(S_ba)
now = 0
rem = sum(S_ba)
S_ab.sort(reverse=True)
for i in range(len(S_ab)):
    if rem <= now: break
    now += S_ab[i]
    ans += 1

print(ans)

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

S_ba = []
S_ab = []
for i in range(N):
    if A[i] < B[i]: S_ba.append(B[i] - A[i])
    else: S_ab.append(A[i] - B[i])
    
ans = 0
tot = 0
S_ab.sort(reverse=True)
for i in range(len(S_ab)):
    # tot += A[i] - B[i]
    if sum(S_ba) <= tot: break
    tot += S_ab[i]
    ans += 1

if sum(S_ba) > sum(S_ab): print(-1)
else : print(len(S_ba) + ans)


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

S_ba = []
S_ab = []
for i in range(N):
    if A[i] < B[i]: S_ba.append(B[i] - A[i])
    elif A[i] > B[i]: S_ab.append(A[i] - B[i])

if sum(S_ba) > sum(S_ab):
    print(-1)
    exit()
    
ans = len(S_ba)
now = 0
rem = sum(S_ba)
S_ab.sort(reverse=True)
for i in range(len(S_ab)):
    if rem <= now: break
    now += S_ab[i]
    ans += 1

print(ans)