[guest@localhost oneedit]$ python3 -m doctest oneedit3.doct 
**********************************************************************
File "oneedit3.doct", line 27, in oneedit3.doct
Failed example:
    f(-1, '', 'a')
Expected:
    ''
Got:
    'a'
**********************************************************************
File "oneedit3.doct", line 39, in oneedit3.doct
Failed example:
    f(0, 'a', 'Rb')
Expected:
    'ab'
Got:
    'ba'
**********************************************************************
File "oneedit3.doct", line 41, in oneedit3.doct
Failed example:
    f(0, 'a', 'RRb')
Expected:
    'ab'
Got:
    'ba'
**********************************************************************
File "oneedit3.doct", line 48, in oneedit3.doct
Failed example:
    f(0, 'a', 'RbLLc')
Expected:
    'cab'
Got:
    'cba'
**********************************************************************
File "oneedit3.doct", line 50, in oneedit3.doct
Failed example:
    f(1, 'a', 'LbRRc')
Expected:
    'bac'
Got:
    'bca'
**********************************************************************
File "oneedit3.doct", line 53, in oneedit3.doct
Failed example:
    f(0, 'a', 'LRb')
Expected:
    'ab'
Got:
    'ba'
**********************************************************************
File "oneedit3.doct", line 55, in oneedit3.doct
Failed example:
    f(0, 'a', 'LLRb')
Expected:
    'ab'
Got:
    'ba'
**********************************************************************
File "oneedit3.doct", line 57, in oneedit3.doct
Failed example:
    f(0, 'a', 'LLLRb')
Expected:
    'ab'
Got:
    'ba'
**********************************************************************
1 items had failures:
   8 of  37 in oneedit3.doct
***Test Failed*** 8 failures.
[guest@localhost oneedit]$

[guest@localhost oneedit]$ ./oneeditcmp.py 
[4.688379621999957, 4.692161592000048, 4.687527015999876]
[2.4444403080001393, 2.4103668410002683, 2.424508097999933]
[2.4301258609998513, 2.449462324999786, 2.420072983999944]
[guest@localhost oneedit]$

def k(p, text, command):
    text = list(text)
    for i in command:
        if i.islower():
            text.insert(p, i)
            p += 1
        if i == 'L':
            p -= 1
        if i == 'R':
            p += 1
        if i == 'X':
            text.pop(p)
    return ''.join(text)

def k(p, text, command):
    text_before = list(text[:p])
    text_after = list(text[p:])
    cur = len(text_after)
    if p < 0:
        p = 0
    if p > len(text):
        p = len(text)
    else:
        for i in command:
            if i.islower():
                text_before.append(i)
                p += 1
            if i == 'L' and text_before != []:
                if p == -1:
                    p = 0
                else:
                    text_after.insert(0, text_before.pop())
                    p -= 1
                    cur += 1
            if i == 'R' and text_after != []:
                if cur == -1:
                    cur = 0
                else:
                    text_before.append(text_after.pop(0))
                    p += 1
                    cur -= 1
            if i == 'X' and text_after != []:
                if cur == -1:
                    cur = 0
                else:
                    text_after.pop(0)
                    cur -= 1
    return text_before + text_after

print(''.join(k(int(input()), str(input()), str(input()))))

def k(p, text, command):
    text = list(text)
    for i in command:
        if i.islower():
            text.insert(p, i)
            p += 1
        if i == 'L':
            p -= 1
        if i == 'R':
            p += 1
        if i == 'X':
            text.pop(p)
    return text

print(''.join(k(int(input()), str(input()), str(input()))))

print(k(0, 'abcd', 'defg'))

print(k(1, k(3, 'abcd', 'X').upper(), 'defg'))

[guest@localhost oneedit]$ python3 -m doctest oneedit4.doct 
**********************************************************************
File "oneedit4.doct", line 27, in oneedit4.doct
Failed example:
    f(-1, '', 'a')
Expected:
    ''
Got:
    'a'
**********************************************************************
1 items had failures:
   1 of  37 in oneedit4.doct
***Test Failed*** 1 failures.
[guest@localhost oneedit]$

[guest@localhost oneedit]$ ./oneeditcmp.py 
[4.911109806999775, 4.887167595000392, 4.959216190999996]
[2.5055572030000803, 2.5339830960001564, 2.497651128000143]
[2.470925120999709, 2.5043154899999536, 2.434840758000064]
[2.506145970000034, 2.4773937669997395, 2.492269657000179]
[guest@localhost oneedit]$