Problem:
 Score : 400 points    Problem Statement A university student, Takahashi, has to take N examinations and pass all of them.
Currently, his readiness for the i -th examination is A_{i} , and according to his investigation, it is known that he needs readiness of at least B_{i} in order to pass the i -th examination.  Takahashi thinks that he may not be able to pass all the examinations, and he has decided to ask a magician, Aoki, to change the readiness for as few examinations as possible so that he can pass all of them, while not changing the total readiness.  For Takahashi, find the minimum possible number of indices i such that A_i and C_i are different, for a sequence C_1, C_2, ..., C_{N} that satisfies the following conditions:   The sum of the sequence A_1, A_2, ..., A_{N} and the sum of the sequence C_1, C_2, ..., C_{N} are equal.  For every i , B_i \leq C_i holds.   If such a sequence C_1, C_2, ..., C_{N} cannot be constructed, print -1 .      Constraints  1 \leq N \leq 10^5  1 \leq A_i \leq 10^9  1 \leq B_i \leq 10^9  A_i and B_i are integers.         Input Input is given from Standard Input in the following format:  N  A_1  A_2  ...  A_{N}  B_1  B_2  ...  B_{N}       Output Print the minimum possible number of indices i such that A_i and C_i are different, for a sequence C_1, C_2, ..., C_{N} that satisfies the conditions.
If such a sequence C_1, C_2, ..., C_{N} cannot be constructed, print -1 .        Sample Input 1 3
2 3 5
3 4 1      Sample Output 1 3  (A_1, A_2, A_3) = (2, 3, 5) and (B_1, B_2, B_3) = (3, 4, 1) . If nothing is done, he cannot pass the first and second exams.
The minimum possible number of indices i such that A_i and C_i are different, 3 , is achieved when:   (C_1, C_2, C_3) = (3, 5, 2)        Sample Input 2 3
2 3 3
2 2 1      Sample Output 2 0  In this case, he has to do nothing in order to pass all the exams.       Sample Input 3 3
17 7 1
25 6 14      Sample Output 3 -1  In this case, no matter what is done, he cannot pass all the exams.       Sample Input 4 12
757232153 372327760 440075441 195848680 354974235 458054863 463477172 740174259 615762794 632963102 529866931 64991604
74164189 98239366 465611891 362739947 147060907 118867039 63189252 78303147 501410831 110823640 122948912 572905212      Sample Output 4 5

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))

if sum(a) < sum(b):
    print('-1')
    exit()

c = []
t = 0
ans = 0
for x, y in zip(a, b):
    if x < y:
        t += y - x
        ans += 1
    else:
        c.append(x - y)

if ans == 0:
    print('0')
    exit()

c.sort(reverse=True)
for p in c:
    t -= p
    ans += 1
    if t < 0:
        break
print(ans)

Solution (Python):
import sys
def input(): return sys.stdin.readline().rstrip()
def main():
    n=int(input())
    A=[int(_) for _ in input().split()]
    B=[int(_) for _ in input().split()]
    sumA,sumB=sum(A),sum(B)
    if sumA<sumB:
        print(-1)
        sys.exit()
    D=[0]*n
    sum_plus,sum_minus,ans=0,0,0
    for i in range(n):
        diff=A[i]-B[i]
        if diff>0:
            D.append(diff)
        elif diff<0:
            sum_minus-=diff
            ans+=1
    D.sort(reverse=True)
    if sum_minus==0:
        print(0)
        sys.exit()
    for d in D:
        ans+=1
        if sum_minus<=d:
            print(ans)
            break
        sum_minus-=d

if __name__=='__main__':
    main()

Solution (Python):
import sys
def input(): return sys.stdin.readline().rstrip()
def main():
    n=int(input())
    A=[int(_) for _ in input().split()]
    B=[int(_) for _ in input().split()]
    sumA=sum(A)
    sumB=sum(B)
    if sumA<sumB:
        print(-1)
        sys.exit()
    D=[0]*n
    sum_plus=0
    sum_minus=0
    ans=0
    for i in range(n):
        diff=A[i]-B[i]
        if diff>0:
            D.append(diff)
        elif diff<0:
            sum_minus-=diff
            ans+=1
    D.sort(reverse=True)
    if sum_minus==0:
        print(0)
        sys.exit()
    for d in D:
        ans+=1
        if sum_minus<=d:
            print(ans)
            break
        sum_minus-=d


if __name__=='__main__':
    main()

Solution (Python):
n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))

if sum(a)<sum(b):
    print(-1)
    exit()

c=[]
ans=0
count=0
for i in range(n):
    c.append(a[i]-b[i])
    if c[i]<0:
        ans+=1
        count+=c[i]

c.sort(reverse=True)

i=0
while count<0:
    count+=c[i]
    ans+=1
    i+=1
    

print(ans)

Solution (Python):
N = int(input())
A = [int(i) for i in input().split()]
B = [int(i) for i in input().split()]

helper = []
need, ans = 0, 0

if sum(A) < sum(B):
  print(-1)
  exit()

for i in range(N):
  if A[i] > B[i]:
    helper.append(A[i] - B[i])
  elif A[i] < B[i]:
    need += B[i] - A[i]
    ans += 1

helper = sorted(helper, reverse=True)
i = 0
while need > 0:
  need -= helper[i]
  i += 1
  ans += 1
print(ans)

Solution (Python):
n = int(input())
As = list(map(int, input().split()))
Bs = list(map(int, input().split()))
from itertools import accumulate
cs = [a-b for a,b in zip(As,Bs)]
cs.sort(reverse=True)

p = [0]+[c for c in cs if c > 0]
m = [c for c in cs if c < 0]


ans = 0

m_all = sum(m)
acc = list(accumulate(p))
ans += len(m)
for i,p in enumerate(acc):
    if p >= -m_all:
        break
ans += i


if sum(As) < sum(Bs):
    print(-1)
else:
    print(ans)

Solution (Python):
import sys, re
def せいすう(): return int(input())
def たくさんのせいすう(): return map(int, input().split())
def せいすうのリスト(): return list(map(int, input().split()))

ようそすう = せいすう()
いま = せいすうのリスト()
もくひょう = せいすうのリスト()

def こうじゅんにならびかえ(リスト):
	return sorted(リスト, reverse=True)

def しゅつりょく(しゅつりょくしたいもじ):
	print(しゅつりょくしたいもじ)

def ごうけい(リスト):
	return sum(リスト)

def ながさ(リスト):
	return len(リスト)

def まとめる(リスト1, リスト2):
	return zip(リスト1, リスト2)

def おわり():
	exit()

def いちをたす(すうじ):
	return すうじ+1

def リストについか(リスト, あたい):
	リスト.append(あたい)

if ごうけい(いま) < ごうけい(もくひょう):
	しゅつりょく(-1)
	おわり()

ふそくリスト = []
よゆうリスト = []

for いまのじゅんびど, もくひょうのじゅんびど in まとめる(いま, もくひょう):
	if いまのじゅんびど < もくひょうのじゅんびど:
		リストについか(ふそくリスト, もくひょうのじゅんびど-いまのじゅんびど)
	else:
		リストについか(よゆうリスト, いまのじゅんびど-もくひょうのじゅんびど)

ふそくこすう = ながさ(ふそくリスト)
if ふそくこすう == 0:
	しゅつりょく(0)
	おわり()

ふそくぶん = ごうけい(ふそくリスト)
よゆうソート = こうじゅんにならびかえ(よゆうリスト)

こたえ = ふそくこすう
おぎなうぶん = 0
for よゆうぶん in よゆうソート:  
	おぎなうぶん += よゆうぶん
	こたえ = いちをたす(こたえ)
	if おぎなうぶん >= ふそくぶん:
		break

しゅつりょく(こたえ)

Solution (Python):
INF = 10 ** 9
MOD = 10 ** 9 + 7
import sys
sys.setrecursionlimit(100000000)
dy = (-1,0,1,0)
dx = (0,1,0,-1)
from  math import factorial


def main():
    n = int(input())
    a = list(map(int,input().split()))
    b = list(map(int,input().split()))
    if sum(a) < sum(b):
        print(-1)
        return
    c = [p - q for p,q in zip(a,b)]
    c.sort(reverse=True)
    minus = 0
    ans = 0
    for i in range(n - 1,-1,-1):
        if c[i] < 0:
            minus += c[i]
            ans += 1
        else:
            break
    
    for i in range(n):
        if minus >= 0:
            break
        minus += c[i]
        ans += 1
    print(ans)
if __name__ == '__main__':
    main()

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

if sum(A) < sum(B):
    print(-1)
else:
    before = [A[i] - B[i] for i in range(N)]
    before.sort()
    diff = [A[i] - B[i] for i in range(N)]
    
    diff.sort()
    left = 0
    right = N - 1
    while True:
        if diff[left] < 0:
            temp = diff[left]
            diff[left] = min(0, diff[left] + diff[right])
            diff[right] -= diff[left] - temp
        if diff[left] == 0:
            if diff[left + 1] < 0:
                left += 1
        if diff[right] == 0:
            if diff[left] < 0:
                right -= 1
        if diff[left] == 0:
            break
    
    cnt = 0
    for i in range(N):
        if before[i] != diff[i]:
            cnt += 1
    print(cnt)

Solution (Python):
N = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
 
if sum(A) < sum(B):
    print(-1)
    exit(0)
 
t = 0
m = 0
L = []
for k in range(N):
    if A[k] > B[k]:
        L.append(A[k]-B[k])
    else:
        m += B[k] - A[k]
        t += 1
 
if m == 0:
    print(0)
    exit(0)
 
L = (sorted(L))[::-1]
for e in L:
    m -= e
    t += 1
    if m <= 0:
        break
print(t)

Solution (Python):
N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
C=[]
cnt=0
fusoku=0 
for i in range(N):
  C.append([A[i],B[i],A[i]-B[i]])
  if A[i]-B[i]<0:
    cnt += 1
    fusoku += abs(A[i]-B[i])
    


  
if sum(A)<sum(B):
  print(-1)
else:
  C.sort(key=lambda x:x[2],reverse=True)
  for t in C:
    if fusoku<=0:
      break
    else:
      cnt +=1
      fusoku -= t[2]
  print(cnt)

Solution (Python):
def main():
    n=int(input())
    a=list(map(int,input().split()))
    b=list(map(int,input().split()))
    c=[]
    minus=0
    ans=0
    if sum(a)<sum(b):
        print(-1)
    else:
        for i in range(n):
            dif=a[i]-b[i]
            if dif>0:
                c.append(dif)
            elif dif<0:
                ans+=1
                minus+=dif
        c.sort(reverse=True)
        i=0
        while minus<0:
            minus+=c[i]
            i+=1
        print(ans+i)
if __name__=="__main__":
    main()

Solution (Python):
n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
suma=sum(a)
sumb=sum(b)
if suma<sumb:
  print(-1)
  exit()
d=[]
for i in range(n):
  d.append(a[i]-b[i])
d.sort()
import bisect
minus=bisect.bisect_left(d,0)
sum_minus=sum(d[:minus])
sum_plus=0
ans=minus
i=1
while sum_plus < -sum_minus:
  sum_plus+=d[-i]
  ans+=1
  i+=1
print(ans)

Solution (Python):
import sys
n = int(input())
a_li = list(map(int,input().split()))
b_li = list(map(int,input().split()))

if sum(a_li)<sum(b_li):
    print(-1)
    sys.exit()

amari_li = []
tarinai_li = []

for  a,b in zip(a_li,b_li):
    if a >= b:
        amari_li.append(a-b)
    else:
        tarinai_li.append(b-a)

t = sum(tarinai_li)



if len(tarinai_li) == 0:
    print(0)
    sys.exit()

amari_li.sort(reverse=True)
count = 0
for a in amari_li:
    t -= a
    count += 1
    if t <= 0:
        break
print(count+len(tarinai_li))

Solution (Python):
n = int(input())
a = [int(x) for x in input().split()]
b = [int(x) for x in input().split()]

if sum(a) < sum(b):
    print(-1)
else:
    x = sorted([a[i]-b[i] for i in range(n)], reverse=True)
    s = -sum(d for d in x if d < 0)
    ans = sum(1 for d in x if d < 0)
    i = 0
    while s > 0:
        s -= x[i]
        ans += 1
        i += 1
    print(ans)

Solution (Python):
from queue import Queue

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

D = [a - b for a, b in zip(A, B)]
Dm = [d for d in D if d < 0]
sum_Dm = abs(sum(Dm))

if sum_Dm == 0:
    print(0)
    exit(0)

Dp = [d for d in D if d > 0]
Dp.sort(reverse=True)

que = Queue()
for d in Dp:
    que.put(d)

cnt = 0
while not que.empty():
    p = que.get()
    cnt += 1
    sum_Dm -= p
    if sum_Dm <= 0:
        print(len(Dm) + cnt)
        exit(0)

print(-1)

Solution (Python):
import heapq
n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))

ans = 0
asum = sum(a)
c = []
csum = 0
num = []
for i,j in zip(a,b):
	if i<j:
		i = i + (j-i)
		ans += 1
	if i>j:
		heapq.heappush(num, -1*(i-j))
	csum += i


while csum>asum and len(num):
	i = heapq.heappop(num)*-1
	csum -= i
	ans += 1

if csum>asum: ans = -1
	
print(ans)

Solution (Python):
n= int(input())
*a,=map(int, input().split( ))
*b,=map(int, input().split( ))
ab = [a[i]-b[i] for i in range(n)]
if sum(ab)<0:
    print(-1)
    exit()

ab.sort()
import bisect
j = bisect.bisect_left(ab,0)
minus = sum(ab[:j])

ans = 0
while minus<0:
    abi = ab.pop()
    minus += abi
    ans += 1
print(ans+j)

Solution (Python):
n = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

from bisect import bisect_left

def solve(n, A, B):
  if sum(A) < sum(B):
    print(-1)
    return

  under = []
  over = []
  for a, b in zip(A, B):
    if a < b: under.append(b-a)
    elif a > b: over.append(a-b)

  over_acc = [0]
  for v in sorted(over, reverse=True):
    over_acc.append(over_acc[-1] + v)

  ans = len(under)
  ans += bisect_left(over_acc, sum(under))
  print(ans)

solve(n, A, B)

Solution (Python):
n = int(input())
A = list(map(int, input().split()))
sumA = sum(A)
B = list(map(int, input().split()))
sumB = sum(B)

if sumA < sumB:
    print(-1)
    exit(0)


flag = True
ok = []
not_ok = []
not_ok_sum = 0
for i in range(n):
    if A[i] < B[i]:
        not_ok.append(i)
        not_ok_sum += A[i]
        flag = False
    else:
        ok.append(A[i] - B[i])

if flag:
    print(0)
    exit(0)

ok.sort()
ok.reverse()










count = 0
current = 0
now_prev = 0
rem = 0
while True:
    now = now_prev + ok[current]
    count += 1
    
    while rem < len(not_ok):
        j = not_ok[rem]
        
        if B[j] - A[j] < now:
            rem += 1
            now -= (B[j] - A[j])
            
            count += 1
        else:
            break
    if rem == len(not_ok):
        break
    else:
        now_prev = now
        current += 1
print(count)

Solution (Python):



N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
if sum(A) < sum(B):
    print(-1)
    exit()
D = []
pre_ans = 0  
for i in range(N):
    if A[i] != B[i]:
        D.append(A[i] - B[i])
        if A[i] < B[i]:
            pre_ans += 1
D = sorted(D)

used = 0
tmp = 0

l, r = 0, len(D)
while r - l > 1:
    
    if tmp + D[l] < 0:
        
        r -= 1
        used += 1
        tmp += D[r]
    tmp += D[l]
    l += 1
print(used + pre_ans)

Solution (Python):
import sys
import numpy as np


def input():
    return sys.stdin.readline().strip()


sys.setrecursionlimit(10 ** 9)


def main():
    N = int(input())
    A = np.array(list(map(int, input().split())))
    B = np.array(list(map(int, input().split())))
    diff = A - B
    lack = -diff[diff < 0]
    enough = diff[diff > 0]
    x = lack.sum()
    enough.sort()
    enough = reversed(enough)
    s = 0
    ans = 0
    for e in enough:
        if s < x:
            s += e
            ans += 1
        else:
            break
    if s < x:
        print(-1)
    else:
        print(len(lack) + ans)


if __name__ == "__main__":
    main()

Solution (Python):
import sys
input = sys.stdin.readline

n = int(input())
a = [int(x) for x in input().split()]
b = [int(x) for x in input().split()]

from copy import deepcopy

c = deepcopy(b)

ans = 0

if sum(a) < sum(b):
    print(-1)
    sys.exit()

diff = 0
ad = []

for i, j in zip(a, b):
    if i == j:
        pass
    elif i > j:
        ad.append(i - j)
    else:
        diff += (j - i)
        ans += 1

ad.sort()

while diff > 0:
    diff -= ad.pop()
    ans += 1

print(ans)

Solution (Python):
import sys
input = sys.stdin.readline

n = int(input())
a = [int(x) for x in input().split()]
b = [int(x) for x in input().split()]

from copy import deepcopy

c = deepcopy(b)

ans = 0

if sum(a) < sum(b):
    print(-1)
    sys.exit()

diff = 0
ad = []

for i, j in zip(a, b):
    if i == j:
        pass
    elif i > j:
        ad.append(i - j)
    else:
        diff += (j - i)
        ans += 1

ad.sort()

while diff > 0:
    diff -= ad.pop()
    ans += 1

print(ans)

Solution (Python):
n = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

if sum(A) < sum(B):
    print(-1)
    exit()
BA = sorted(i - j for i, j in zip(A, B))

not_enough = 0
ans = 0
for ba in BA:
    if ba < 0:
        not_enough += ba
        ans += 1
    else:
        break
for ba in BA[::-1]:
    if not_enough >= 0:
        break
    not_enough += ba
    ans += 1
print(ans)

Solution (Python):
N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
if sum(A)<sum(B):
    print(-1)
else:
    a=0
    s=0
    l=[]
    for i in range(N):
        if A[i]<B[i]:
            a+=1
            s+=B[i]-A[i]
        else:
            l.append(A[i]-B[i])
    l.sort(reverse=1)
    for i in range(len(l)):
        if s<=0:
            break
        s-=l[i]
        a+=1
    print(a)

Solution (Python):

if False:
    N,M=map(int,input().split())
    A=[int(i) for i in input().split()]
    B=[int(i) for i in input().split()]
    A.sort()
    B.sort()
    ans='YES'
    if N<M:
        ans='NO'
    else:
        while B:
            a=A.pop()
            b=B.pop()
            if b>a:
                ans='NO'
                break
    print(ans)


if False:
    A,B=map(int,input().split())
    def uruu(n):
        ret=0
        ret+=n//4
        ret-=n//100
        ret+=n//400
        return ret
    print(uruu(B)-uruu(A-1))


if False:
    S=input()
    stack=list(S[::-1])
    
    user=[]
    s=stack.pop()
    while stack:
        
        if s=="@":
            tmp=''
            x=stack.pop()
            while not(x in ('@',' ')):
                
                tmp+=x
                if not stack:
                    break
                x=stack.pop()
            user.append(tmp)
            s=x
        else:
            s=stack.pop()
    user=list(set(user))
    user.sort()
    for u in user:
        if u:
            print(u)


if False: 
    S=input()
    hi=['hi'*i for i in range(1,10)]
    print('Yes' if S in hi else 'No')


if True:
    N=int(input())
    A=[int(i) for i in input().split()]
    B=[int(i) for i in input().split()]
    S=list(zip(A,B))
    if sum(A)<sum(B):
        print(-1)
    else:
        C=[]
        for s in S:
            a,b=s
            if a<b: C.append(s)
        CA=sum(C[i][0] for i in range(len(C)))
        CB=sum(C[i][1] for i in range(len(C)))
        S.sort(key=lambda x: x[0]-x[1])
        while CA<CB:
            c,d=S.pop()
            CA+=c
            CB+=d
            C.append((c,d))
        print(len(C))

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
if sum(a)<sum(b):
    result = -1
else:
    count = 0
    over = [0]
    result = 0
    for i in range(n):
        if a[i]>b[i]:
            over.append(a[i]-b[i])
        elif a[i]<b[i]:
            count += b[i]-a[i]
            result += 1
    over.sort(reverse=True)
    i = 0
    while count > 0:
        result += 1
        count -= over[i]
        i += 1
print(result)

Solution (Python):
import sys
input = sys.stdin.readline

n = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))

ans = 0
C = []
D = []
for i in range(n):
    if B[i] > A[i]:
        C.append(B[i] - A[i])
        ans += 1
    elif A[i] > B[i]:
        D.append(A[i] - B[i])

s = sum(C)


D.sort(reverse=True)
i = 0
while i < len(D) and s > 0:
    s -= D[i]
    ans += 1
    i += 1

if s > 0:
    ans = -1
print(ans)

Solution (Python):
"""
import random
import functools
import copy
import bisect
import array
import re
import collections
import heapq
import fractions
import itertools
import string
import math
from operator import itemgetter as ig
from bisect import bisect_left, bisect_right, insort_left, insort_right
from itertools import permutations, combinations, product, accumulate, groupby
from heapq import heappush, heappop
from collections import deque, defaultdict, Counter
import sys
sys.setrecursionlimit(10 ** 7)


inf = 10 ** 20
INF = float("INF")
mod = 10 ** 9 + 7
dd = [(-1, 0), (0, 1), (1, 0), (0, -1)]
ddn = dd + [(-1, 1), (1, 1), (1, -1), (-1, -1)]
ddn9 = ddn + [(0, 0)]
'''for dx, dy in dd:
        nx = j + dx; ny = i + dy
            if 0 <= nx < w and 0 <= ny < h:'''
"""

import sys


def main():
    N = int(input())
    A = list(map(int, input().split()))
    B = list(map(int, input().split()))
    D = []
    S = 0
    cnt = 0
    for i in range(N):
        d = B[i] - A[i]
        if d > 0:
            S += d
            cnt += 1
        else:
            D.append(-d)
            if len(D) == N:
                print(0)
                sys.exit()
    D.sort()
    ans = 0
    for i in range(len(D)-1, -1, -1):
        ans += 1
        if D[i] < S:
            S -= D[i]
            if i == 0:
                if S > 0:
                    print(-1)
                    sys.exit()
        else:
            break
    print(ans + cnt)


if __name__ == '__main__':
    main()

Solution (Python):
n = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
p = []
ans = 0
x = sum(A)
k = 0
for i in range(n):
    if A[i] < B[i]:
        ans += 1
        k += A[i] - B[i]
    elif A[i] > B[i]:
        p.append(A[i] - B[i])
        
p.sort(reverse=True)
for i in p:
    if k >= 0:
        break
    k += i
    ans += 1

if k >= 0:
    print(ans)
else:
    print(-1)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
p, s, ans = [], 0, 0
for i, (a, b) in enumerate(zip(A, B)):
    if a > b:
        p.append(a-b)
    elif a < b:
        s += b-a
        ans += 1
p.sort(reverse=1)
for x in p:
    if s > 0:
        s -= x
        ans += 1
else:
    if s > 0:
        ans = -1
print(ans)

Solution (Python):
N = int(input())
A = list(map(int, input().split())) 
B = list(map(int, input().split())) 

if sum(A) < sum(B):
    print(-1)
else:
    minus = 0
    plus_list = []
    ans = 0
    for a, b in zip(A, B):
        if a - b < 0:
            ans += 1
            minus += b - a
        elif a - b > 0:
            plus_list.append(a - b)

    plus_list.sort(reverse=True)
    for p in plus_list:
        if minus <= 0:
            break
        ans += 1
        minus -= p
    if minus > 0:
        print(-1)
    else:
        print(ans)

Solution (Python):
N = int(input())
A = list(map(int, input().split())) 
B = list(map(int, input().split())) 

if sum(A) < sum(B):
    print(-1)
else:
    minus = 0
    plus_list = []
    ans = 0
    for a, b in zip(A, B):
        if a - b < 0:
            ans += 1
            minus += b - a
        elif a - b > 0:
            plus_list.append(a - b)

    plus_list.sort(reverse=True)
    for p in plus_list:
        if minus <= 0:
            break
        ans += 1
        minus -= p

    print(ans)

Solution (Python):
n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
c=[]
for i in range(n):
    c.append(a[i]-b[i])
c=sorted(c,reverse=1)
if sum(c)<0:
    print(-1)
    exit()
d=0
e=0
f=0
for i in range(n):
    if c[i]<0:
        d+=c[i]
        e+=1
for i in range(n):
    if f>=abs(d):
        break
    f+=c[i]
print(e+i)

Solution (Python):
import sys
input = sys.stdin.buffer.readline

def main():
    N = int(input())
    a = list(map(int,input().split()))
    b = list(map(int,input().split()))
    m,p = [],[]
    
    for x,y in zip(a,b):
        if x > y:
            p.append(x-y)
        elif x < y:
            m.append(y-x)

    ch = sum(m)
    p.sort(reverse=True)
    ans = len(m)
    l = 0
    while ch > 0:
        if l == len(p):
            print(-1)
            exit()
        else:
            ch -= p[l]
            ans += 1
            l += 1
            
    print(ans)

if __name__ == "__main__":
    main()

Solution (Python):

from collections import defaultdict,deque
from heapq import heappush, heappop
from bisect import bisect_left, bisect_right
import sys, random, itertools, math
sys.setrecursionlimit(10**5)
input = sys.stdin.readline
sqrt = math.sqrt
def LI(): return list(map(int, input().split()))
def LF(): return list(map(float, input().split()))
def LI_(): return list(map(lambda x: int(x)-1, input().split()))
def II(): return int(input())
def IF(): return float(input())
def S(): return input().rstrip()
def LS(): return S().split()
def IR(n): return [II() for _ in range(n)]
def LIR(n): return [LI() for _ in range(n)]
def FR(n): return [IF() for _ in range(n)]
def LFR(n): return [LI() for _ in range(n)]
def LIR_(n): return [LI_() for _ in range(n)]
def SR(n): return [S() for _ in range(n)]
def LSR(n): return [LS() for _ in range(n)]
mod = 1000000007
inf = 1e10


def solve():
    n = II()
    a = LI()
    b = LI()
    if sum(a) < sum(b):
        print(-1)
    else:
        tmp = 0
        ans = 0
        ab = list(map(lambda x: x[0] - x[1], zip(a, b)))
        ab.sort()
        for i in ab:
            if i < 0:
                ans += 1
                tmp += i
            else:
                break
        for i in ab[::-1]:
            if tmp < 0:
                if i > 0:
                    ans += 1
                    tmp += i
        print(ans)
    return



if __name__ == '__main__':
    solve()

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
aff = [0]*N

if sum(A) < sum(B):
    print(-1)
else:
    need = 0
    ans = 0
    for i in range(N):
        aff[i] = A[i] - B[i]
    
    aff = sorted(aff)
    affrev = aff[::-1]
    
    for i in range(N):
        if aff[i] < 0:
            ans += 1
            need -= aff[i]
        else:
            break
    
    j = 0
    while need > 0:
        need -= affrev[j]
        ans += 1
        j += 1
    
    print(ans)

Solution (Python):
n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
dif=[]

s=0
ans=0
for g in range(n):
    if a[g]<b[g]:
        s+=b[g]-a[g]
        ans+=1
    elif a[g]>b[g]:
        dif.append(a[g]-b[g])
dif.sort(reverse=True)

if s==0:
    print(0)
    exit()

for l in range(len(dif)):
    s-=dif[l]
    ans+=1
    if s<0:
        break

if s<=0:
    print(ans)
else:
    print(-1)

Solution (Python):
N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
pluslist=[]
minuslist=[]
cnt=0
ms=0
for i in range(N):
    if A[i]-B[i]<0:
        minuslist.append(A[i]-B[i])
    elif A[i]-B[i]>0:
        pluslist.append(A[i]-B[i])

ms=sum(minuslist)
cnt=cnt+len(minuslist)
pluslist.sort(reverse=True)
idx=0

while (ms<0)and(idx<len(pluslist)):
    ms=ms+pluslist[idx]
    cnt=cnt+1
    idx=idx+1
if ms<0:
    print("-1")
else:
    print(cnt)

Solution (Python):
import sys
input = sys.stdin.readline

n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
check = [0] * n
for i in range(n):
    check[i] = a[i] - b[i]
check.sort()
m_check = sorted(check, reverse=True)
m_cnt = 0
p = 0
ans = 0
for i in range(n):
    if check[i] < 0:
        p += check[i]
        ans += 1
    else:
        if p >= 0:
            print(ans)
            exit()
        else:
            p += m_check[m_cnt]
            m_cnt += 1
            ans += 1
if p >= 0:
    print(ans)
else:
    print(-1)

Solution (Python):
import sys
n=int(input())
a=list(map(int,input().split()));b=list(map(int,input().split()))
if sum(a)<sum(b): print(-1),sys.exit()
x=sorted([a[i]-b[i] for i in range(n)],reverse=True)
s=-sum(d for d in x if d<0)
ans=sum(1 for d in x if d<0)
i=0
while s>0:
    s-=x[i]
    ans+=1
    i+=1
print(ans)

Solution (Python):
N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
SA=sum(A)
SB=sum(B)
if SA<SB:
    print(-1)
    exit()
ans=0
p=[]
m=[]
for i in range(N):
    a=A[i]-B[i]
    if a>=0:
        p.append(a)
    else:
        m.append(a)
if len(m)==0:
    print(0)
    exit()
M=sum(m)
M=abs(M)
p.sort(reverse=True)
for i in range(len(p)):
    if M<=0:
        break
    ans+=1
    M=M-p[i]
ans+=len(m)
print(ans)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

diff = [a - b for a, b in zip(A, B)]
diff.sort()
if sum(A) < sum(B):
    print(-1)
else:
    minus_sum = 0
    ans = 0
    for i in range(N):
        if diff[i] < 0:
            minus_sum += diff[i]
            ans += 1
        else:
            break

    for i in range(N - 1, 0, -1):
        if minus_sum >= 0:
            break
        else:
            ans += 1
            minus_sum += diff[i]

    print(ans)

Solution (Python):
n = int(input())
aa = list(map(int, input().split()))
bb = list(map(int, input().split()))
"""
先頭からなめていって、
A. ai < biなら対処が必要⇒変更確定
B. ai == biなら変更不要で確定
C. ai > biなら他に融通する可能性あり⇒保留
Aのケースの不足数の総和を計算し、Cの差分の大きいものから順に使っていく。
Cのheapqを作成するのかな？いったんリストでやってみるか
"""
if sum(aa) < sum(bb):
    print(-1)
else:
    total_diff = 0
    margin = []
    modified = 0
    for i in range(n):
        if aa[i] < bb[i]:
            modified += 1
            total_diff += bb[i] - aa[i]
        elif aa[i] > bb[i]:
            margin.append(aa[i]-bb[i])
    margin.sort(reverse=True)
    while total_diff > 0:
        modified += 1
        t = margin.pop(0)
        total_diff -= t
    print(modified)

Solution (Python):
import heapq
n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
if sum(a) < sum(b) :
  print(-1)
else :
  ans = 0
  lack = 0
  que = [0]
  heapq.heapify(que)
  for i in range(n) :
    a[i] -= b[i]
    if a[i] < 0 :
      ans += 1
      lack -= a[i]
    else :
      heapq.heappush(que,-a[i])
  while lack > 0 :
    m = heapq.heappop(que)
    lack += m
    ans += 1
  print(ans)

Solution (Python):
N = int(input())
taka = list(map(int,input().split()))
exam = list(map(int,input().split()))

sa = list()

for t,e in zip(taka,exam):
  sa.append(t-e)
sa = sorted(sa)

minus = list(filter(lambda x:x<0,sa))
plus = list(filter(lambda x:x>0,sa))

sum_plus = 0
sum_minus = sum(minus)
if sum_minus == 0:
  print(0)
else:
  for idx,p in enumerate(plus[::-1]):
    sum_plus += p
    if sum_plus>=-sum_minus:
      print(idx+1+len(minus))
      break
  else:
    print(-1)

Solution (Python):

from sys import setrecursionlimit
setrecursionlimit(10**6)
from collections import Counter
def inputlist(): return [int(j) for j in input().split()]

N = int(input())
A = inputlist()
B = inputlist()
C = [A[i]-B[i] for i in range(N)]
s = sum(C)
if s < 0:
    print(-1)
    exit()
C.sort()
ans = 0
for i in range(N):
    if C[i] <0:
        pass
    elif C[i] <= s:
        ans +=1
        s -= C[i]
    else:
        break
print(N-ans)

Solution (Python):
N = int(input())
A = [int(x) for x in input().split()]
B = [int(x) for x in input().split()]

if sum(A) < sum(B) :
    print(-1)
    exit()

les = 0
ans = 0
Over = []
for i in range(N) :
    Over.append(A[i]-B[i])
    if A[i] < B[i] :
        les += B[i] - A[i]
        ans += 1

Over.sort(reverse = True)
for ov in Over :
    if les <= 0 :
        print(ans)
        break
    les -= ov
    ans += 1

Solution (Python):
from collections import deque
n = int(input())
a = [int(i) for i in input().split()]
b = [int(i) for i in input().split()]
c = [ai - bi for ai, bi in zip(a, b)]
if sum(c) < 0:
    print(-1)
    exit()
c.sort()
minus = deque()
for ci in c:
    if ci >= 0:
        break
    minus.append(ci)
ans = len(minus)
s = sum(minus) * (-1)
plus = 0
idx = -1
while s > plus:
    plus += c[idx]
    ans += 1
    idx -= 1
print(ans)