Buggy python submission (verdict: Runtime Error):
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))


ups = []
downs = []
eqs = []
for i in range(3):
    if A[i] < B[i]:
        ups.append((A[i], B[i]))
    elif A[i] == B[i]:
        eqs.append((A[i], B[i]))
    else:
        downs.append((A[i], B[i]))
ans = N

if len(eqs) == 3:
    print(N)
    exit()

if len(ups) == 0:
    tmp = A
    A = B
    B = tmp
    tmp = ups
    ups = downs
    downs = tmp

if len(ups) == 3:
    gold_diff = B[0]-A[0]
    silver_diff = B[1]-A[1]
    cupper_diff = B[2]-A[2]
    for gold in range(N//A[0]+1):
        left = N - gold*A[0]
        for silver in range(left//A[1]+1):
            cupper = (left - silver*A[1])//A[2]
            tmp_ans = (N
                       + gold*gold_diff
                       + silver*silver_diff
                       + cupper*cupper_diff)
            ans = max(ans, tmp_ans)
    print(ans)
elif len(ups) == 2:
    gold_diff = ups[0][1]-ups[0][0]
    silver_diff = ups[1][1]-ups[1][0]
    for gold in range(N//ups[0][0]+1):
        left = N - gold*ups[0][0]
        silver = left // ups[1][0]
        tmp_ans = (N
                   + gold*gold_diff
                   + silver*silver_diff)
        ans = max(ans, tmp_ans)
    if len(downs) == 1:
        diff = downs[0][0]-downs[0][1]
        ans += (ans // downs[0][1]) * diff
    print(ans)
elif len(ups) == 1:
    bbans = N + (N//ups[0][0])*(ups[0][1]-ups[0][0])
    if len(downs) == 2:
        tmp_ans = bbans
        gold_diff = downs[0][0]-downs[0][1]
        silver_diff = downs[1][0]-downs[1][1]
        for gold in range(bbans//downs[0][1]+1):
            left = bbans - gold*downs[0][1]
            silver = left // downs[1][1]
            tmp_ans = (bbans
                       + gold*gold_diff
                       + silver*silver_diff)
            ans = max(ans, tmp_ans)
    elif len(downs) == 1:
        ans =bbans + (bbans//downs[0][1])*(downs[0][0]-downs[0][1])
    else:
        ans = 
    print(ans)


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


ups = []
downs = []
eqs = []
for i in range(3):
    if A[i] < B[i]:
        ups.append((A[i], B[i]))
    elif A[i] == B[i]:
        eqs.append((A[i], B[i]))
    else:
        downs.append((A[i], B[i]))
ans = N

if len(eqs) == 3:
    print(N)
    exit()

if len(ups) == 0:
    tmp = A[:]
    A = B[:]
    B = tmp[:]
    ups = []
    downs = []
    eqs = []
    for i in range(3):
        if A[i] < B[i]:
            ups.append((A[i], B[i]))
        elif A[i] == B[i]:
            eqs.append((A[i], B[i]))
        else:
            downs.append((A[i], B[i]))

if len(ups) == 3:
    gold_diff = B[0]-A[0]
    silver_diff = B[1]-A[1]
    cupper_diff = B[2]-A[2]
    for gold in range(N//A[0]+1):
        left = N - gold*A[0]
        for silver in range(left//A[1]+1):
            cupper = (left - silver*A[1])//A[2]
            tmp_ans = (N
                       + gold*gold_diff
                       + silver*silver_diff
                       + cupper*cupper_diff)
            ans = max(ans, tmp_ans)
elif len(ups) == 2:
    gold_diff = ups[0][1]-ups[0][0]
    silver_diff = ups[1][1]-ups[1][0]
    for gold in range(N//ups[0][0]+1):
        left = N - gold*ups[0][0]
        silver = left // ups[1][0]
        tmp_ans = (N
                   + gold*gold_diff
                   + silver*silver_diff)
        ans = max(ans, tmp_ans)
    if len(downs) == 1:
        diff = downs[0][0]-downs[0][1]
        ans += (ans // downs[0][1]) * diff
elif len(ups) == 1:
    nowN = N + (N//ups[0][0])*(ups[0][1]-ups[0][0])
    if len(downs) == 2:
        gold_diff = downs[0][0]-downs[0][1]
        silver_diff = downs[1][0]-downs[1][1]
        for gold in range(nowN//downs[0][1]+1):
            left = nowN - gold*downs[0][1]
            silver = left // downs[1][1]
            tmp_ans = (nowN
                       + gold*gold_diff
                       + silver*silver_diff)
            ans = max(ans, tmp_ans)
    elif len(downs) == 1:
        ans = nowN + (nowN//downs[0][1])*(downs[0][0]-downs[0][1])
    else:
        ans = nowN
print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))


ups = []
downs = []
eqs = []
for i in range(3):
    if A[i] < B[i]:
        ups.append((A[i], B[i]))
    elif A[i] == B[i]:
        eqs.append((A[i], B[i]))
    else:
        downs.append((A[i], B[i]))
ans = N

if len(eqs) == 3:
    print(N)
    exit()

if len(ups) == 0:
    tmp = A
    A = B
    B = tmp
    tmp = ups
    ups = downs
    downs = tmp

if len(ups) == 3:
    gold_diff = B[0]-A[0]
    silver_diff = B[1]-A[1]
    cupper_diff = B[2]-A[2]
    for gold in range(N//A[0]+1):
        left = N - gold*A[0]
        for silver in range(left//A[1]+1):
            cupper = (left - silver*A[1])//A[2]
            tmp_ans = (N
                       + gold*gold_diff
                       + silver*silver_diff
                       + cupper*cupper_diff)
            ans = max(ans, tmp_ans)
    print(ans)
elif len(ups) == 2:
    gold_diff = ups[0][1]-ups[0][0]
    silver_diff = ups[1][1]-ups[1][0]
    for gold in range(N//ups[0][0]+1):
        left = N - gold*ups[0][0]
        silver = left // ups[1][0]
        tmp_ans = (N
                   + gold*gold_diff
                   + silver*silver_diff)
        ans = max(ans, tmp_ans)
    if len(downs) == 1:
        diff = downs[0][0]-downs[0][1]
        ans += (ans // downs[0][1]) * diff
    print(ans)
elif len(ups) == 1:
    bbans += (N//ups[0][0])*(ups[0][1]-ups[0][0])
    if len(downs) == 2:
        tmp_ans = bbans
        gold_diff = downs[0][0]-downs[0][1]
        silver_diff = downs[1][0]-downs[1][1]
        for gold in range(tmp_ans//downs[0][1]+1):
            left = tmp_ans - gold*downs[0][1]
            silver = left // downs[1][1]
            tmp_ans = (tmp_ans
                       + gold*gold_diff
                       + silver*silver_diff)
            ans = max(ans, tmp_ans)
    elif len(downs) == 1:
        ans += (ans//downs[0][1])*(downs[0][0]-downs[0][1])
    print(ans)


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


ups = []
downs = []
eqs = []
for i in range(3):
    if A[i] < B[i]:
        ups.append((A[i], B[i]))
    elif A[i] == B[i]:
        eqs.append((A[i], B[i]))
    else:
        downs.append((A[i], B[i]))
ans = N

if len(eqs) == 3:
    print(N)
    exit()

if len(ups) == 0:
    tmp = A[:]
    A = B[:]
    B = tmp[:]
    ups = []
    downs = []
    eqs = []
    for i in range(3):
        if A[i] < B[i]:
            ups.append((A[i], B[i]))
        elif A[i] == B[i]:
            eqs.append((A[i], B[i]))
        else:
            downs.append((A[i], B[i]))

if len(ups) == 3:
    gold_diff = B[0]-A[0]
    silver_diff = B[1]-A[1]
    cupper_diff = B[2]-A[2]
    for gold in range(N//A[0]+1):
        left = N - gold*A[0]
        for silver in range(left//A[1]+1):
            cupper = (left - silver*A[1])//A[2]
            tmp_ans = (N
                       + gold*gold_diff
                       + silver*silver_diff
                       + cupper*cupper_diff)
            ans = max(ans, tmp_ans)
elif len(ups) == 2:
    gold_diff = ups[0][1]-ups[0][0]
    silver_diff = ups[1][1]-ups[1][0]
    for gold in range(N//ups[0][0]+1):
        left = N - gold*ups[0][0]
        silver = left // ups[1][0]
        tmp_ans = (N
                   + gold*gold_diff
                   + silver*silver_diff)
        ans = max(ans, tmp_ans)
    if len(downs) == 1:
        diff = downs[0][0]-downs[0][1]
        ans += (ans // downs[0][1]) * diff
elif len(ups) == 1:
    nowN = N + (N//ups[0][0])*(ups[0][1]-ups[0][0])
    if len(downs) == 2:
        gold_diff = downs[0][0]-downs[0][1]
        silver_diff = downs[1][0]-downs[1][1]
        for gold in range(nowN//downs[0][1]+1):
            left = nowN - gold*downs[0][1]
            silver = left // downs[1][1]
            tmp_ans = (nowN
                       + gold*gold_diff
                       + silver*silver_diff)
            ans = max(ans, tmp_ans)
    elif len(downs) == 1:
        ans = nowN + (nowN//downs[0][1])*(downs[0][0]-downs[0][1])
    else:
        ans = nowN
print(ans)