Buggy python submission (verdict: Runtime Error):
N = int(input())
a1, a2, a3 = map(int, input().split())
b1, b2, b3 = map(int, input().split())
A = [a1, a2, a3]
B = [b1, b2, b3]
if (a1<=b1 and a2<=b2 and a3<=b3) or (a1>=b1 and a2>=b2 and a3>=b3):
    if a1>b1 or a2>b2 or a3>b3:
        A, B = B, A
    dp = [[-float("inf")]*(N+1+5050) for _ in range(4)]
    dp[0][0] = 0
    for i in range(3):
        ai = A[i]
        bi = B[i]
        for j in range(N+1):

            dp[i+1][j] = max(dp[i][j], dp[i+1][j-ai]+bi)
    print(max(dp[3]))
    assert False
    #print(dp[3][:30])
else:
    C, D = [], []
    for a, b in zip(A, B):
        if a <= b:
            C.append([a,b])
        else:
            D.append([b, a])

    if len(C)==1:
        a, b = C[0]
        q, n = divmod(N, a)
        N_ = q*b + n
    else:
        N_ = N
        (a1, b1), (a2, b2) = C
        for i in range(N + 1):
            j = N - i
            q1, n1 = divmod(i, a1)
            q2, n2 = divmod(j, a2)
            N_ = max(N_, q1 * b1 + q2 * b2 + n1 + n2)

    if len(D)==1:
        a, b = D[0]
        q, n = divmod(N_, a)
        print(q*b + n)
        #print("a")
    else:
        ans = N_
        (a1, b1), (a2, b2) = D
        for i in range(N_+1):
            j = N_ - i
            q1, n1 = divmod(i, a1)
            q2, n2 = divmod(j, a2)
            ans = max(ans, q1*b1+q2*b2+n1+n2)
        print(ans)


Fixed submission:
N = int(input())
a1, a2, a3 = map(int, input().split())
b1, b2, b3 = map(int, input().split())
A = [a1, a2, a3]
B = [b1, b2, b3]
if (a1<=b1 and a2<=b2 and a3<=b3) or (a1>=b1 and a2>=b2 and a3>=b3):
    if a1>b1 or a2>b2 or a3>b3:
        A, B = B, A
    dp = [[-float("inf")]*(N+1) for _ in range(4)]
    dp[0][0] = 0
    for i in range(3):
        ai = A[i]
        bi = B[i]
        for j in range(N+1):
            if j-ai>=0:
                dp[i+1][j] = max(dp[i][j], dp[i+1][j-ai]+bi)
            else:
                dp[i+1][j] = dp[i][j]
    ans = 0
    for i, v in enumerate(dp[3]):
        ans = max(ans, v+(N-i))
    print(ans)

    #print(dp[3][:30])
else:
    C, D = [], []
    for a, b in zip(A, B):
        if a <= b:
            C.append([a, b])
        else:
            D.append([b, a])

    if len(C)==1:
        a, b = C[0]
        q, n = divmod(N, a)
        N_ = q*b + n
    else:
        N_ = N
        (a1, b1), (a2, b2) = C
        for i in range(N + 1):
            j = N - i
            q1, n1 = divmod(i, a1)
            q2, n2 = divmod(j, a2)
            N_ = max(N_, q1 * b1 + q2 * b2 + n1 + n2)

    if len(D)==1:
        a, b = D[0]
        q, n = divmod(N_, a)
        print(q*b + n)
        #print("a")
    else:
        ans = N_
        (a1, b1), (a2, b2) = D
        for i in range(N_+1):
            j = N_ - i
            q1, n1 = divmod(i, a1)
            q2, n2 = divmod(j, a2)
            ans = max(ans, q1*b1+q2*b2+n1+n2)
        print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
a1, a2, a3 = map(int, input().split())
b1, b2, b3 = map(int, input().split())
A = [a1, a2, a3]
B = [b1, b2, b3]
if (a1<=b1 and a2<=b2 and a3<=b3) or (a1>=b1 and a2>=b2 and a3>=b3):
    if a1>b1 or a2>b2 or a3>b3:
        A, B = B, A
    dp = [[-float("inf")]*(N+1+5050) for _ in range(4)]
    dp[0][0] = 0
    for i in range(3):
        ai = A[i]
        bi = B[i]
        for j in range(N+1):

            dp[i+1][j] = max(dp[i][j], dp[i+1][j-ai]+bi)
    print(max(dp[3]))
    #print(dp[3][:30])
else:
    C, D = [], []
    for a, b in zip(A, B):
        if a <= b:
            C.append([a,b])
        else:
            D.append([b, a])

    if len(C)==1:
        a, b = C[0]
        q, n = divmod(N, a)
        N_ = q*b + n
    else:
        N_ = N
        (a1, b1), (a2, b2) = C
        for i in range(N + 1):
            j = N - i
            q1, n1 = divmod(i, a1)
            q2, n2 = divmod(j, a2)
            N_ = max(N_, q1 * b1 + q2 * b2 + n1 + n2)

    if len(D)==1:
        a, b = D[0]
        q, n = divmod(N_, a)
        print(q*b + n)
        #print("a")
    else:
        assert False
        ans = N_
        (a1, b1), (a2, b2) = D
        for i in range(N_+1):
            j = N_ - i
            q1, n1 = divmod(i, a1)
            q2, n2 = divmod(j, a2)
            ans = max(ans, q1*b1+q2*b2+n1+n2)
        print(ans)


Fixed submission:
N = int(input())
a1, a2, a3 = map(int, input().split())
b1, b2, b3 = map(int, input().split())
A = [a1, a2, a3]
B = [b1, b2, b3]
if (a1<=b1 and a2<=b2 and a3<=b3) or (a1>=b1 and a2>=b2 and a3>=b3):
    if a1>b1 or a2>b2 or a3>b3:
        A, B = B, A
    dp = [[-float("inf")]*(N+1) for _ in range(4)]
    dp[0][0] = 0
    for i in range(3):
        ai = A[i]
        bi = B[i]
        for j in range(N+1):
            if j-ai>=0:
                dp[i+1][j] = max(dp[i][j], dp[i+1][j-ai]+bi)
            else:
                dp[i+1][j] = dp[i][j]
    ans = 0
    for i, v in enumerate(dp[3]):
        ans = max(ans, v+(N-i))
    print(ans)

    #print(dp[3][:30])
else:
    C, D = [], []
    for a, b in zip(A, B):
        if a <= b:
            C.append([a, b])
        else:
            D.append([b, a])

    if len(C)==1:
        a, b = C[0]
        q, n = divmod(N, a)
        N_ = q*b + n
    else:
        N_ = N
        (a1, b1), (a2, b2) = C
        for i in range(N + 1):
            j = N - i
            q1, n1 = divmod(i, a1)
            q2, n2 = divmod(j, a2)
            N_ = max(N_, q1 * b1 + q2 * b2 + n1 + n2)

    if len(D)==1:
        a, b = D[0]
        q, n = divmod(N_, a)
        print(q*b + n)
        #print("a")
    else:
        ans = N_
        (a1, b1), (a2, b2) = D
        for i in range(N_+1):
            j = N_ - i
            q1, n1 = divmod(i, a1)
            q2, n2 = divmod(j, a2)
            ans = max(ans, q1*b1+q2*b2+n1+n2)
        print(ans)