Buggy python submission (verdict: Runtime Error):
M = 1000000007
n, k = map(int, input().split())
l = list(map(int, input().split()))
k1 = k
pos = []
neg = []
zero = []
for i in l:
    if i > 0: pos.append(i)
    if i < 0: neg.append(i)
    if i == 0: zero.append(i)
pos.sort(reverse = True)
neg.sort()


if k == 1:
    if len(pos) > 0: print(pos[0] % M)
    elif len(zero) > 0: print(0)
    else: print(neg[0] % M)
    exit(0)

check = 0
if k % 2 == 1:
    check = 1
    k -= 3

p1, p2 = 0, 0
n1, n2 = len(pos), len(neg)

ans = 1
ch1, ch2 = 1, 1
while 1:
    if k == 0: break
    
    if p1 + 1 >= n1: ch1 = 0 
    if p2 + 1 >= n2: ch2 = 0
    
    if ch1 and ch2:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        t2 = neg[p2] * neg[p2 + 1]
        if t1 >= t2:
            p1 += 2
            ans = (ans * t1) % M
        else:
            p2 += 2
            ans = (ans * t2) % M
    elif ch1:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        ans = (ans * t1) % M
        p1 += 2
    elif ch2:
        k -= 2
        t2 = neg[p2] * neg[p2 + 1]
        ans = (ans * t2) % M
        p2 += 2
    else: break

if k != 0:
    if p1 + 1 >= n1 and p2 + 1 >= n2:
        ans = (ans * pos[p1]) % M
        ans = (ans * neg[p2]) % M
else:
    ch1, ch2 = 1, 1
    if check:
        if p1 + 2 >= n1: ch1 = 0 
        if p2 + 1 >= n2: ch2 = 0
        
        if ch1 and ch2:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            t2 = neg[p2] * neg[p2 + 1] * pos[p1]
            if t1 >= t2:
                ans = (ans * t1) % M
            else:
                ans = (ans * t2) % M
        elif ch1:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            ans = (ans * t1) % M
        elif ch2:
            if p1 < n1:
                t2 = neg[p2] * neg[p2 + 1] * pos[p1]
                ans = (ans * t2) % M
            else:
                if len(zero) > 0: ans = 0
                else:
                    tmp = []
                    for i in range(n):
                        if l[i] >= 0: tmp.append([l[i], 1])
                        else: tmp.append([-l[i], 0])
                    tmp.sort()
                    Ans = 1
                    for i in range(k1):
                        if tmp[i][1] == 1: Ans = (Ans * tmp[i][0]) % M
                        else: Ans = (Ans * tmp[i][0] * -1) % M
                    ans = Ans
        else:
            if len(zero) > 0: ans = 0
            else:
                t2 = neg[p2] * pos[p1] * pos[p1 + 1]
                ans = (ans * t2) % M
print(ans)

Fixed submission:
M = 1000000007
n, k = map(int, input().split())
l = list(map(int, input().split()))
k1 = k
pos = []
neg = []
zero = []
for i in l:
    if i > 0: pos.append(i)
    if i < 0: neg.append(i)
    if i == 0: zero.append(i)
pos.sort(reverse = True)
neg.sort()


if k == 1:
    if len(pos) > 0: print(pos[0] % M)
    elif len(zero) > 0: print(0)
    else: print(neg[0] % M)
    exit(0)

check = 0
if k % 2 == 1:
    check = 1
    k -= 3

p1, p2 = 0, 0
n1, n2 = len(pos), len(neg)

ans = 1
ch1, ch2 = 1, 1
while 1:
    if k == 0: break
    
    if p1 + 1 >= n1: ch1 = 0 
    if p2 + 1 >= n2: ch2 = 0
    
    if ch1 and ch2:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        t2 = neg[p2] * neg[p2 + 1]
        if t1 >= t2:
            p1 += 2
            ans = (ans * t1) % M
        else:
            p2 += 2
            ans = (ans * t2) % M
    elif ch1:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        ans = (ans * t1) % M
        p1 += 2
    elif ch2:
        k -= 2
        t2 = neg[p2] * neg[p2 + 1]
        ans = (ans * t2) % M
        p2 += 2
    else: break

if k != 0:
    if len(zero) > 0: ans = 0
    else:
        ans = (ans * pos[p1]) % M
        ans = (ans * neg[p2]) % M
else:
    ch1, ch2 = 1, 1
    if check:
        if p1 + 2 >= n1: ch1 = 0 
        if p2 + 1 >= n2: ch2 = 0
        
        if ch1 and ch2:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            t2 = neg[p2] * neg[p2 + 1] * pos[p1]
            if t1 >= t2:
                ans = (ans * t1) % M
            else:
                ans = (ans * t2) % M
        elif ch1:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            ans = (ans * t1) % M
        elif ch2:
            if p1 < n1:
                t2 = neg[p2] * neg[p2 + 1] * pos[p1]
                ans = (ans * t2) % M
            else:
                if len(zero) > 0: ans = 0
                else:
                    tmp = []
                    for i in range(n):
                        if l[i] >= 0: tmp.append([l[i], 1])
                        else: tmp.append([-l[i], 0])
                    tmp.sort()
                    Ans = 1
                    for i in range(k1):
                        if tmp[i][1] == 1: Ans = (Ans * tmp[i][0]) % M
                        else: Ans = (Ans * tmp[i][0] * -1) % M
                    ans = Ans
        else:
            if len(zero) > 0: ans = 0
            else:
                t2 = neg[p2] * pos[p1] * pos[p1 + 1]
                ans = (ans * t2) % M
print(ans)

Buggy python submission (verdict: Runtime Error):
M = 1000000007
n, k = map(int, input().split())
l = list(map(int, input().split()))
k1 = k
pos = []
neg = []
zero = []
for i in l:
    if i > 0: pos.append(i)
    if i < 0: neg.append(i)
    if i == 0: zero.append(i)
pos.sort(reverse = True)
neg.sort()


if k == 1: 
    print(pos[0] % M)
    exit(0)

check = 0
if k % 2 == 1:
    check = 1
    k -= 3

p1, p2 = 0, 0
n1, n2 = len(pos), len(neg)

ans = 1
ch1, ch2 = 1, 1
while 1:
    if k == 0: break
    
    if p1 + 1 >= n1: ch1 = 0 
    if p2 + 1 >= n2: ch2 = 0
    
    if ch1 and ch2:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        t2 = neg[p2] * neg[p2 + 1]
        if t1 >= t2:
            p1 += 2
            ans = (ans * t1) % M
        else:
            p2 += 2
            ans = (ans * t2) % M
    elif ch1:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        ans = (ans * t1) % M
        p1 += 2
    elif ch2:
        k -= 2
        t2 = neg[p2] * neg[p2 + 1]
        ans = (ans * t2) % M
        p2 += 2
    else: break

if k != 0:
    if p1 + 1 >= n1 and p2 + 1 >= n2:
        ans = (ans * pos[p1]) % M
        ans = (ans * neg[p2]) % M
else:
    ch1, ch2 = 1, 1
    if check:
        if p1 + 2 >= n1: ch1 = 0 
        if p2 + 1 >= n2: ch2 = 0
        
        if ch1 and ch2:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            t2 = neg[p2] * neg[p2 + 1] * pos[p1]
            if t1 >= t2:
                ans = (ans * t1) % M
            else:
                ans = (ans * t2) % M
        elif ch1:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            ans = (ans * t1) % M
        elif ch2:
            if p1 < n1:
                t2 = neg[p2] * neg[p2 + 1] * pos[p1]
                ans = (ans * t2) % M
            else:
                if len(zero) > 0: ans = 0
                else:
                    tmp = []
                    for i in range(n):
                        if l[i] >= 0: tmp.append([l[i], 1])
                        else: tmp.append([-l[i], 0])
                    tmp.sort()
                    Ans = 1
                    for i in range(k1):
                        if tmp[i][1] == 1: Ans = (Ans * tmp[i][0]) % M
                        else: Ans = (Ans * tmp[i][0] * -1) % M
                    ans = Ans
        else:
            if len(zero) > 0: ans = 0
            else:
                t2 = neg[p2] * pos[p1] * pos[p1 + 1]
                ans = (ans * t2) % M
print(ans)

Fixed submission:
M = 1000000007
n, k = map(int, input().split())
l = list(map(int, input().split()))
k1 = k
pos = []
neg = []
zero = []
for i in l:
    if i > 0: pos.append(i)
    if i < 0: neg.append(i)
    if i == 0: zero.append(i)
pos.sort(reverse = True)
neg.sort()


if k == 1:
    if len(pos) > 0: print(pos[0] % M)
    elif len(zero) > 0: print(0)
    else: print(neg[0] % M)
    exit(0)

check = 0
if k % 2 == 1:
    check = 1
    k -= 3

p1, p2 = 0, 0
n1, n2 = len(pos), len(neg)

ans = 1
ch1, ch2 = 1, 1
while 1:
    if k == 0: break
    
    if p1 + 1 >= n1: ch1 = 0 
    if p2 + 1 >= n2: ch2 = 0
    
    if ch1 and ch2:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        t2 = neg[p2] * neg[p2 + 1]
        if t1 >= t2:
            p1 += 2
            ans = (ans * t1) % M
        else:
            p2 += 2
            ans = (ans * t2) % M
    elif ch1:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        ans = (ans * t1) % M
        p1 += 2
    elif ch2:
        k -= 2
        t2 = neg[p2] * neg[p2 + 1]
        ans = (ans * t2) % M
        p2 += 2
    else: break

if k != 0:
    if len(zero) > 0: ans = 0
    else:
        ans = (ans * pos[p1]) % M
        ans = (ans * neg[p2]) % M
else:
    ch1, ch2 = 1, 1
    if check:
        if p1 + 2 >= n1: ch1 = 0 
        if p2 + 1 >= n2: ch2 = 0
        
        if ch1 and ch2:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            t2 = neg[p2] * neg[p2 + 1] * pos[p1]
            if t1 >= t2:
                ans = (ans * t1) % M
            else:
                ans = (ans * t2) % M
        elif ch1:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            ans = (ans * t1) % M
        elif ch2:
            if p1 < n1:
                t2 = neg[p2] * neg[p2 + 1] * pos[p1]
                ans = (ans * t2) % M
            else:
                if len(zero) > 0: ans = 0
                else:
                    tmp = []
                    for i in range(n):
                        if l[i] >= 0: tmp.append([l[i], 1])
                        else: tmp.append([-l[i], 0])
                    tmp.sort()
                    Ans = 1
                    for i in range(k1):
                        if tmp[i][1] == 1: Ans = (Ans * tmp[i][0]) % M
                        else: Ans = (Ans * tmp[i][0] * -1) % M
                    ans = Ans
        else:
            if len(zero) > 0: ans = 0
            else:
                t2 = neg[p2] * pos[p1] * pos[p1 + 1]
                ans = (ans * t2) % M
print(ans)

Buggy python submission (verdict: Runtime Error):
M = 1000000007
n, k = map(int, input().split())
l = list(map(int, input().split()))
k1 = k
pos = []
neg = []
zero = []
for i in l:
    if i > 0: pos.append(i)
    if i < 0: neg.append(i)
    if i == 0: zero.append(i)
pos.sort(reverse = True)
neg.sort()

check = 0
if k % 2 == 1:
    check = 1
    k -= 3

p1, p2 = 0, 0
n1, n2 = len(pos), len(neg)

ans = 1
ch1, ch2 = 1, 1
while 1:
    if k == 0: break
    
    if p1 + 1 >= n1: ch1 = 0 
    if p2 + 1 >= n2: ch2 = 0
    
    if ch1 and ch2:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        t2 = neg[p2] * neg[p2 + 1]
        if t1 >= t2:
            p1 += 2
            ans = (ans * t1) % M
        else:
            p2 += 2
            ans = (ans * t2) % M
    elif ch1:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        ans = (ans * t1) % M
        p1 += 2
    elif ch2:
        k -= 2
        t2 = neg[p2] * neg[p2 + 1]
        ans = (ans * t2) % M
        p2 += 2
    else: break

if k != 0:
    if p1 + 1 >= n1 and p2 + 1 >= n2:
        ans = (ans * pos[p1]) % M
        ans = (ans * neg[p2]) % M
else:
    ch1, ch2 = 1, 1
    if check:
        if p1 + 2 >= n1: ch1 = 0 
        if p2 + 1 >= n2: ch2 = 0
        
        if ch1 and ch2:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            t2 = neg[p2] * neg[p2 + 1] * pos[p1]
            if t1 >= t2:
                ans = (ans * t1) % M
            else:
                ans = (ans * t2) % M
        elif ch1:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            ans = (ans * t1) % M
        elif ch2:
            if p1 < n1:
                t2 = neg[p2] * neg[p2 + 1] * pos[p1]
                ans = (ans * t2) % M
            else:
                if len(zero) > 0: ans = 0
                else:
                    tmp = []
                    for i in range(n):
                        if l[i] >= 0: tmp.append([l[i], 1])
                        else: tmp.append([-l[i], 0])
                    tmp.sort()
                    Ans = 1
                    for i in range(k1):
                        if tmp[i][1] == 1: Ans = (Ans * tmp[i][0]) % M
                        else: Ans = (Ans * tmp[i][0] * -1) % M
                    ans = Ans
        else:
            if len(zero) > 0: ans = 0
            else:
                t2 = neg[p2] * pos[p1] * pos[p1 + 1]
                ans = (ans * t2) % M
print(ans)

Fixed submission:
M = 1000000007
n, k = map(int, input().split())
l = list(map(int, input().split()))
k1 = k
pos = []
neg = []
zero = []
for i in l:
    if i > 0: pos.append(i)
    if i < 0: neg.append(i)
    if i == 0: zero.append(i)
pos.sort(reverse = True)
neg.sort()


if k == 1:
    if len(pos) > 0: print(pos[0] % M)
    elif len(zero) > 0: print(0)
    else: print(neg[0] % M)
    exit(0)

check = 0
if k % 2 == 1:
    check = 1
    k -= 3

p1, p2 = 0, 0
n1, n2 = len(pos), len(neg)

ans = 1
ch1, ch2 = 1, 1
while 1:
    if k == 0: break
    
    if p1 + 1 >= n1: ch1 = 0 
    if p2 + 1 >= n2: ch2 = 0
    
    if ch1 and ch2:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        t2 = neg[p2] * neg[p2 + 1]
        if t1 >= t2:
            p1 += 2
            ans = (ans * t1) % M
        else:
            p2 += 2
            ans = (ans * t2) % M
    elif ch1:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        ans = (ans * t1) % M
        p1 += 2
    elif ch2:
        k -= 2
        t2 = neg[p2] * neg[p2 + 1]
        ans = (ans * t2) % M
        p2 += 2
    else: break

if k != 0:
    if len(zero) > 0: ans = 0
    else:
        ans = (ans * pos[p1]) % M
        ans = (ans * neg[p2]) % M
else:
    ch1, ch2 = 1, 1
    if check:
        if p1 + 2 >= n1: ch1 = 0 
        if p2 + 1 >= n2: ch2 = 0
        
        if ch1 and ch2:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            t2 = neg[p2] * neg[p2 + 1] * pos[p1]
            if t1 >= t2:
                ans = (ans * t1) % M
            else:
                ans = (ans * t2) % M
        elif ch1:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            ans = (ans * t1) % M
        elif ch2:
            if p1 < n1:
                t2 = neg[p2] * neg[p2 + 1] * pos[p1]
                ans = (ans * t2) % M
            else:
                if len(zero) > 0: ans = 0
                else:
                    tmp = []
                    for i in range(n):
                        if l[i] >= 0: tmp.append([l[i], 1])
                        else: tmp.append([-l[i], 0])
                    tmp.sort()
                    Ans = 1
                    for i in range(k1):
                        if tmp[i][1] == 1: Ans = (Ans * tmp[i][0]) % M
                        else: Ans = (Ans * tmp[i][0] * -1) % M
                    ans = Ans
        else:
            if len(zero) > 0: ans = 0
            else:
                t2 = neg[p2] * pos[p1] * pos[p1 + 1]
                ans = (ans * t2) % M
print(ans)

Buggy python submission (verdict: Runtime Error):
M = 1000000007
n, k = map(int, input().split())
l = list(map(int, input().split()))
pos = []
neg = []
zero = []
for i in l:
    if i > 0: pos.append(i)
    if i < 0: neg.append(i)
    if i == 0: zero.append(i)
pos.sort(reverse = True)
neg.sort()

check = 0
if k % 2 == 1:
    check = 1
    k -= 3

p1, p2 = 0, 0
n1, n2 = len(pos), len(neg)

ans = 1
ch1, ch2 = 1, 1
while 1:
    if k == 0: break
    
    if p1 + 1 >= n1: ch1 = 0 
    if p2 + 1 >= n2: ch2 = 0
    
    if ch1 and ch2:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        t2 = neg[p2] * neg[p2 + 1]
        if t1 >= t2:
            p1 += 2
            ans = (ans * t1) % M
        else:
            p2 += 2
            ans = (ans * t2) % M
    elif ch1:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        ans = (ans * t1) % M
        p1 += 2
    elif ch2:
        k -= 2
        t2 = neg[p2] * neg[p2 + 1]
        ans = (ans * t2) % M
        p2 += 2
    else: break

if k != 0:
    if p1 + 1 >= n1 and p2 + 1 >= n2:
        ans = (ans * pos[p1]) % M
        ans = (ans * neg[p2]) % M
else:
    ch1, ch2 = 1, 1
    if check:
        if p1 + 2 >= n1: ch1 = 0 
        if p2 + 1 >= n2: ch2 = 0
        
        if ch1 and ch2:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            t2 = neg[p2] * neg[p2 + 1] * pos[p1]
            if t1 >= t2:
                ans = (ans * t1) % M
            else:
                ans = (ans * t2) % M
        elif ch1:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            ans = (ans * t1) % M
        elif ch2:
            if p1 < n:
                t2 = neg[p2] * neg[p2 + 1] * pos[p1]
                ans = (ans * t2) % M
            else:
                if len(zero) > 0: ans = 0
                else:
                    tmp = []
                    for i in range(n):
                        if l[i] >= 0: tmp.append(l[i], 1)
                        else: tmp.append(-l[i], 0)
                    tmp.sort()
                    Ans = 1
                    for i in range(k):
                        if tmp[i][1] == 1: Ans = (Ans * tmp[i][0]) % M
                        else: Ans = (Ans * tmp[i][0] * -1) % M
                    ans = Ans
        else:
            if len(zero) > 0: ans = 0
            else:
                t2 = neg[p2] * pos[p1] * pos[p1 + 1]
                ans = (ans * t2) % M
print(ans)

Fixed submission:
M = 1000000007
n, k = map(int, input().split())
l = list(map(int, input().split()))
k1 = k
pos = []
neg = []
zero = []
for i in l:
    if i > 0: pos.append(i)
    if i < 0: neg.append(i)
    if i == 0: zero.append(i)
pos.sort(reverse = True)
neg.sort()


if k == 1:
    if len(pos) > 0: print(pos[0] % M)
    elif len(zero) > 0: print(0)
    else: print(neg[0] % M)
    exit(0)

check = 0
if k % 2 == 1:
    check = 1
    k -= 3

p1, p2 = 0, 0
n1, n2 = len(pos), len(neg)

ans = 1
ch1, ch2 = 1, 1
while 1:
    if k == 0: break
    
    if p1 + 1 >= n1: ch1 = 0 
    if p2 + 1 >= n2: ch2 = 0
    
    if ch1 and ch2:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        t2 = neg[p2] * neg[p2 + 1]
        if t1 >= t2:
            p1 += 2
            ans = (ans * t1) % M
        else:
            p2 += 2
            ans = (ans * t2) % M
    elif ch1:
        k -= 2
        t1 = pos[p1] * pos[p1 + 1]
        ans = (ans * t1) % M
        p1 += 2
    elif ch2:
        k -= 2
        t2 = neg[p2] * neg[p2 + 1]
        ans = (ans * t2) % M
        p2 += 2
    else: break

if k != 0:
    if len(zero) > 0: ans = 0
    else:
        ans = (ans * pos[p1]) % M
        ans = (ans * neg[p2]) % M
else:
    ch1, ch2 = 1, 1
    if check:
        if p1 + 2 >= n1: ch1 = 0 
        if p2 + 1 >= n2: ch2 = 0
        
        if ch1 and ch2:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            t2 = neg[p2] * neg[p2 + 1] * pos[p1]
            if t1 >= t2:
                ans = (ans * t1) % M
            else:
                ans = (ans * t2) % M
        elif ch1:
            t1 = pos[p1] * pos[p1 + 1] * pos[p1 + 2]
            ans = (ans * t1) % M
        elif ch2:
            if p1 < n1:
                t2 = neg[p2] * neg[p2 + 1] * pos[p1]
                ans = (ans * t2) % M
            else:
                if len(zero) > 0: ans = 0
                else:
                    tmp = []
                    for i in range(n):
                        if l[i] >= 0: tmp.append([l[i], 1])
                        else: tmp.append([-l[i], 0])
                    tmp.sort()
                    Ans = 1
                    for i in range(k1):
                        if tmp[i][1] == 1: Ans = (Ans * tmp[i][0]) % M
                        else: Ans = (Ans * tmp[i][0] * -1) % M
                    ans = Ans
        else:
            if len(zero) > 0: ans = 0
            else:
                t2 = neg[p2] * pos[p1] * pos[p1 + 1]
                ans = (ans * t2) % M
print(ans)