Buggy python submission (verdict: Runtime Error):
try:
    s1=(input(''))
    if len(s1)==4:
        check=list((s1))
    assert bool(int(check[0]+check[1])<=12) != bool(int(check[2]+check[3])<=12)
    if int(check[0]+check[1])<=12:
        print("MMYY")
    elif int(check[2]+check[3])<=12:
        print("YYMM")
except AssertionError:
    if int(check[0]+check[1])<=12 and int(check[2]+check[3])<=12:
        print("AMBIGUOUS")
    else:
        print("NA")


Fixed submission:
n,k=map(int, input("").split(' '))
assert n>=k>=1
assert 1<=n<=50

s=input('')
assert ("a","b","c" in s)

z=list((s))
z[k-1]=z[k-1].swapcase()

for i in z:
    print(i, end='')

Buggy python submission (verdict: Runtime Error):
try:
    s1=(input(''))
    if len(s1)==4:
        check=list((s1))
    assert bool(int(check[0]+check[1])<=12) != bool(int(check[2]+check[3])<=12)
    if int(check[0]+check[1])<=12:
        print("MMYY")
    elif int(check[2]+check[3])<=12:
        print("YYMM")
except AssertionError:
    if int(check[0]+check[1])<=12 and int(check[2]+check[3])<=12:
        print("AMBIGUOUS")
    else:
        print("NA")


Fixed submission:
n,k=map(int, input("").split(' '))
assert n>=k>=1
assert 1<=n<=50

s=input('')
assert ("a","b","c" in s)

z=list((s))
z[k-1]=z[k-1].swapcase()

for i in z:
    print(i, end='')

Buggy python submission (verdict: Runtime Error):
try:
    s1=(input(''))
    if len(s1)==4:
        check=list((s1))
    assert bool(int(check[0]+check[1])<=12) != bool(int(check[2]+check[3])<=12)
    if int(check[0]+check[1])<=12:
        print("MMYY")
    elif int(check[2]+check[3])<=12:
        print("YYMM")
except AssertionError:
    if int(check[0]+check[1])<=12 and int(check[2]+check[3])<=12:
        print("AMBIGUOUS")
    else:
        print("NA")

Fixed submission:
n,k=map(int, input("").split(' '))
assert n>=k>=1
assert 1<=n<=50

s=input('')
assert ("a","b","c" in s)

z=list((s))
z[k-1]=z[k-1].swapcase()

for i in z:
    print(i, end='')

Buggy python submission (verdict: Runtime Error):
try:
    s1=(input(''))
    if len(s1)==4:
        check=list((s1))
    assert bool(int(check[0]+check[1])<=12) != bool(int(check[2]+check[3])<=12)
    if int(check[0]+check[1])<=12:
        print("MMYY")
    elif int(check[2]+check[3])<=12:
        print("YYMM")
except AssertionError:
    if int(check[0]+check[1])<=12 and int(check[2]+check[3])<=12:
        print("AMBIGUOUS")
    else:
        print("NA")

Fixed submission:
n,k=map(int, input("").split(' '))
assert n>=k>=1
assert 1<=n<=50

s=input('')
assert ("a","b","c" in s)

z=list((s))
z[k-1]=z[k-1].swapcase()

for i in z:
    print(i, end='')

Buggy python submission (verdict: Runtime Error):
n,k=map(int, input("").split(' '))
s=input('')
if len(s)=n:
  slist=lis((s))
  swapcase(slist[k-1])
 
for i in range(0,len(slist)-1):
  print(slist[i], end=' ')
  

Fixed submission:
n,k=map(int, input("").split(' '))
assert n>=k>=1
assert 1<=n<=50

s=input('')
assert ("a","b","c" in s)

z=list((s))
z[k-1]=z[k-1].swapcase()

for i in z:
    print(i, end='')

Buggy python submission (verdict: Runtime Error):
  1 N, K = input().split()
  2 S = input()
  3 K = int(K)
  4 li = list(S)
  5 li[K-1] = chr(ord(S[K-1])+32)
  6 print(''.join(li))

Fixed submission:
N, K = input().split()
S = input()
K = int(K)
li = list(S)
li[K-1] = chr(ord(S[K-1])+32)
print(''.join(li))