qyliang/CodeNanoFix huggingface dataset:
Buggy code:
import sys
s = input()
i = 1 
s1 = ''
while i <= len(s):
  s1 += s[-i]
  i += 1
s2 = s1
while s2 != '':
  if s2[0:5] == 'maerd':
    s2 = s2[6:]
  elif s2[0:7] == 'remaerd':
    s2 = s2[8:]
  elif s2[0:5] == 'esare':
    s2 = s2[6:]
  elif s2[0:6] == 'resare':
    s2 = s2[7:]
  else:
    print('NO')
    sys.exit()
print('YES')

Fixed code:
import sys
s = input()
i = 1 
s1 = ''
while i <= len(s):
  s1 += s[-i]
  i += 1
s2 = s1
while s2 != '':
  if s2[0:5] == 'maerd':
    s2 = s2[5:]
  elif s2[0:7] == 'remaerd':
    s2 = s2[7:]
  elif s2[0:5] == 'esare':
    s2 = s2[5:]
  elif s2[0:6] == 'resare':
    s2 = s2[6:]
  else:
    print('NO')
    sys.exit()
print('YES')
Buggy code:
s = input()

for i in range(10 ** 5):
    if s[:5] == "dream":
        if s[:7] == "dreamer":
            s = s[7:]
        else:
            s = s[5:]
    elif s[:5] == "erase":
        if s[:6] == "eraser":
            s = s[6:]
        else:
            s = s[5:]
    else:
        if len(s) > 0:
            print("NO")
            break
        else:
            print("YES")
            break

Fixed code:
s = input()[::-1]
for i in range(10 ** 5):
    if s[:5] == "dream"[::-1] or s[:5] == "erase"[::-1]:
        s = s[5:]
    elif s[:7] == "dreamer"[::-1]:
        s = s[7:]
    elif s[:6] == "eraser"[::-1]:
        s = s[6:]
    else:
        if len(s) > 0:
            print("NO")
            break
        else:
            print("YES")
            break
Buggy code:
S = input()

f = 0
while(1):
    print(S)
    if len(S) <= 4:
        break
    if S[:5] == "dream":
        if len(S) == 5:
            f = 1
            break
        elif len(S) == 6:
            break
        if S[:7] == "dreamer":
            if len(S) == 7:
                f = 1
                break
            if S[7] != "a":
                S = S[7:]
                continue
            else:
                S = S[5:]
        else:
            S = S[5:]
    elif S[:5] == "erase":
        if len(S) == 5:
            f = 1
            break
        if S[:6] == "eraser":
            if len(S) == 6:
                f = 1
                break
            if S[6] != "a":
                S = S[7:]
                continue
            else:
                S = S[:5]
        else:
            S = S[5:]
    else:
        break

if f == 0:
    print("NO")
else:
    print("YES")


Fixed code:
S = input()

f = 0
while(1):
    #print(S)
    if len(S) <= 4:
        break
    if S[:5] == "dream":
        if len(S) == 5:
            f = 1
            break
        elif len(S) == 6:
            break
        if S[:7] == "dreamer":
            if len(S) == 7:
                f = 1
                break
            if S[7] != "a":
                S = S[7:]
                continue
            else:
                S = S[5:]
        else:
            S = S[5:]
    elif S[:5] == "erase":
        if len(S) == 5:
            f = 1
            break
        if S[:6] == "eraser":
            if len(S) == 6:
                f = 1
                break
            if S[6] != "a":
                S = S[6:]
                continue
            else:
                S = S[:5]
        else:
            S = S[5:]
    else:
        break

if f == 0:
    print("NO")
else:
    print("YES")
Buggy code:
import sys
s=input()
while(s):
  if(s[:7]=="dreamer"):
    s=s[7:]
  elif(s[:5]=="dream"):
    s=s[5:]
  elif(s[:6]=="eraser"):
    s=s[6:]
  elif(s[:5]=="erase"):
    s=s[5:]
  else:
    print("NO")
    sys.exit()
print("YES")

Fixed code:
import sys
s=input()
while(s):
  if(s[-7:]=="dreamer"):
    s=s[:-7]
  elif(s[-5:]=="dream"):
    s=s[:-5]
  elif(s[-6:]=="eraser"):
    s=s[:-6]
  elif(s[-5:]=="erase"):
    s=s[:-5]
  else:
    print("NO")
    sys.exit()
print("YES")
Buggy code:
import re

def main():
    s = list(input())
    sr = ''.join(list(reversed(s)))
    t = ['dream', 'dreamer', 'erase', 'eraser']
    tr = list()
    for i in t:
        tr.append(''.join(list(reversed(i))))
    while sr:
        flag = False
        for i in tr:
            if sr.startswith(i):
                sr = sr.replace(i ,"")
                flag = True
        if not flag:
            print('NO')
            break
    print('YES')
if __name__ == '__main__':
    main()

Fixed code:
import re

def main():
    s = list(input())
    sr = ''.join(list(reversed(s)))
    t = ['dream', 'dreamer', 'erase', 'eraser']
    tr = list()
    for i in t:
        tr.append(''.join(list(reversed(i))))
    while sr:
        flag = False
        for i in tr:
            if sr.startswith(i):
                sr = sr.replace(i ,'', 1)
                flag = True
        if not flag:
            print('NO')
            break
        if sr == '':
            print('YES')
            break
if __name__ == '__main__':
    main()
Buggy code:
s = input()
s_r_l = list(reversed(s))
s_r = ''.join(list(s_r_l))
# print(s_r)
t = str()
d = ['dream','dreamer','erase','eraser']
d_r = []
for i in d:
    i_s_l = list(reversed(i))
    i_s = ''.join(list(i_s_l))
    d_r.append(i_s)
# print(d_r)
while len(s_r)>0:
    judge = [s_r.endswith(i) for i in d_r]
    if any(judge):
        target = d_r[judge.index(True)]
        # print(target)
        s_r = s_r[len(target):]
        if len(s_r) == 0:
            print("YES")
    else:
        print("NO")
        break

Fixed code:
s = input()
s_r_l = list(reversed(s))
s_r = ''.join(list(s_r_l))
# print(s_r)
t = str()
d = ['dream','dreamer','erase','eraser']
d_r = []
for i in d:
    i_s_l = list(reversed(i))
    i_s = ''.join(list(i_s_l))
    d_r.append(i_s)
# print(d_r)
while len(s_r)>0:
    judge = [s_r.startswith(i) for i in d_r]
    if any(judge):
        # print(judge)
        target = d_r[judge.index(True)]
        # print(target)
        s_r = s_r[len(target):]
        # print(s_r)
        if len(s_r) == 0:
            print("YES")
    else:
        print("NO")
        break
Buggy code:

s = input()

t = ''

s = s.replace('eraser', '').replace('erase', '').replace('dreamer', '').replace('dream', '')
print(s)

if s == t:
    print('YES')
else:
    print('NO')


Fixed code:
s = input()
if s.replace("eraser","").replace("erase","").replace("dreamer","").replace("dream",""):
    print("NO")
else:
    print("YES")
Buggy code:
T = input()
lenT = len(T)
bc = T.count("dreamer")
T = T.replace("dreamer","xxxxxxx",bc)
ac = T.count("eraser")
T = T.replace("eraser","xxxxxx",ac)
cc = T.count("erase")
T = T.replace("erase","xxxxx",cc)
dc = T.count("dream")
T = T.replace("dream","xxxxx",dc)
D = T.count("x")
print(T)
print(D)
if D == lenT:
  print("YES")
elif lenT > D:
  print("NO")
else :
  print("error")

Fixed code:
T = input()
lenT = len(T)
ac = T.count("eraser")
T = T.replace("eraser","xxxxxx",ac)
cc = T.count("erase")
T = T.replace("erase","xxxxx",cc)
bc = T.count("dreamer")
T = T.replace("dreamer","xxxxxxx",bc)
dc = T.count("dream")
T = T.replace("dream","xxxxx",dc)
D = T.count("x")
if D == lenT:
  print("YES")
elif lenT > D:
  print("NO")
else :
  print("error")
Buggy code:
st=input()
c="0"
j="0"
u="0"
for i in st:
    if i=="d" and u=="0" and c=="0":
        u="d"
        j="1"
    elif i=="r" and u=="d":
        u="r1"
    elif i=="e" and u=="r1":
        u="e1"
    elif i=="a" and u=="e1":
        u="a1"
    elif i=="m" and u=="a1":
        u="0"
        
    elif i=="e" and u=="0":
        u="e2"
        if j !="1":
            c="1"
    elif i=="r" and u=="e2":
        u="0"
        j="2"
    elif i=="a" and u=="0" and j=="2":
        u="a2"
    elif i=="s" and u=="a2":
        u="s"
    elif i=="e" and u=="s":
        u="0"
        c="0"
        j="3"
    elif i=="r" and j=="3":
        j="0"
    else:
        print("NO")
        exit(0)
if u=="0":
    print("YES")
else:
    print("NO")

Fixed code:
st=input()
c="0"
j="0"
u="0"
for i in st:
    if i=="d" and u=="0" and c=="0":
        u="d"
        j="1"
    elif i=="r" and u=="d":
        u="r1"
    elif i=="e" and u=="r1":
        u="e1"
    elif i=="a" and u=="e1":
        u="a1"
    elif i=="m" and u=="a1":
        u="0"
        
    elif i=="e" and u=="0" and c=="0":
        u="e2"
        if j !="1":
            c="1"
    elif i=="r" and u=="e2":
        u="0"
        j="2"
    elif i=="a" and u=="0" and j=="2":
        u="a2"
    elif i=="s" and u=="a2":
        u="s"
    elif i=="e" and u=="s":
        u="0"
        c="0"
        j="3"
    elif i=="r" and u=="0" and j=="3":
        j="0"
    else:
        print("NO")
        exit(0)
if u=="0"and c=="0":
    print("YES")
else:
    print("NO")
Buggy code:
S = input()
flag = 0
S = S[::-1]
while True:
    if S.startswith("maerd") or S.startswith("esare"):
        S = S[5:]
    elif S.startswith("remaerd"):
        S = S[7:]
    elif S.startswith("reesare"):
        S = S[6:]
    elif S == "":
        break
    else:
        flag = 1
        break
print("YES" if flag == 0 else "NO")


Fixed code:
S = input()
flag = 0
S = S[::-1]
while True:
    if S.startswith("maerd") or S.startswith("esare"):
        S = S[5:]
    elif S.startswith("remaerd"):
        S = S[7:]
    elif S.startswith("resare"):
        S = S[6:]
    elif S == "":
        break
    else:
        flag = 1
        break
print("YES" if flag == 0 else "NO")
Buggy code:
s = input()

import re
output ="NO"
s = re.sub('dreamer', '', s)
s = re.sub('dream', '', s)
s = re.sub('eraser', '', s)
s = re.sub('erase', '', s)
if s == "":
    output = "YES"
print(output)


Fixed code:
s = input()

import re
output ="NO"
s = re.sub('eraser', '', s)
s = re.sub('erase', '', s)
s = re.sub('dreamer', '', s)
s = re.sub('dream', '', s)
if s == "":
    output = "YES"
print(output)
Buggy code:
S = input()
lst = ["dreamer", "dream", "eraser", "erase"]
n = 0

while len(S) != 0:
    i = 0
    for s in lst:
        i = S.find(s, n)
        if i == 0:
            if s == lst[0] and S.find(lst[3], n) == 5:
                print(S.find(lst[3], n))
                pass
            else:
                S = S[len(s) :]
                break
    if i != 0:
        print("NO")
        exit()

print("YES")

Fixed code:
S = input()
lst = ["dreamer", "dream", "eraser", "erase"]
n = 0

while len(S) != 0:
    i = 0
    for s in lst:
        i = S.find(s, n)
        if i == 0:
            if s == lst[0] and S.find(lst[3], n) == 5:
                pass
            else:
                S = S[len(s) :]
                break
    if i != 0:
        print("NO")
        exit()

print("YES")
Buggy code:
s_init = input()
s_list = list(reversed(s_init))
s = ''.join(s_list)
t = ""
words = ["maerd", "remaerd", 'esare', 'resare']
s_list = list(s)
t_list = list(t)
while s != t:
    if len(s_list) < len(t_list):
        break
    elif t == 'gameover':
        break
    for word in words:
        if s.startswith(t + word):
            t = t + word
            break
        else:
            t = 'gameover'
if s == t:
    print('YES')
else:
    print('NO')


Fixed code:
s_init = input()
s_list = list(reversed(s_init))
s = ''.join(s_list)
t = ""
words = ["maerd", "remaerd", 'esare', 'resare']
s_list = list(s)
t_list = list(t)
while s != t:
    t_fixed = t
    if len(s_list) < len(t_list):
        break
    elif t == 'gameover':
        break
    else:
        for word in words:
            if s.startswith(t + word):
                t = t + word
                break
        if t == t_fixed:
            t = 'gameover'
if s == t:
    print('YES')
else:
    print('NO')
Buggy code:
s = input()
# s = "dreamerase"
L = ["eraser", "dreamer", "erase", "dream"]
i = 0
f = 0
while i < len(s):
    if s[i:i+6] == "eraser":
        i += 6
        break
    elif s[i:i+6] == "dreamer" and (len(s) == i+6 or s[i+6:i+8] != "as"):
        i += 6
        break
    if s[i:i+5] == "erase" or s[i:i+5] == "dream":
        i += 5
        break
    else:
        f = 1
        break

if f == 0:
    print("YES")
else:
    print("NO")


Fixed code:
s = input()
# s = "dreamerase"
L = ["eraser", "dreamer", "erase", "dream"]
i = 0
f = 0
while i < len(s):
    if s[i:i+6] == "eraser" and (len(s) == i+6 or s[i+6:i+8] != "as"):
        i += 6
    elif s[i:i+7] == "dreamer" and (len(s) == i+7 or s[i+7:i+9] != "as"):
        i += 7
    elif s[i:i+5] == "erase" or s[i:i+5] == "dream":
        i += 5
    else:
        f = 1
        break

if f == 0:
    print("YES")
else:
    print("NO")
Buggy code:
s = input()
s = s.replace("dream","")
s = s.replace("dreamer","")
s = s.replace("erase","")
s = s.replace("eraser","")
if len(s)==0:
  print("YES")
else:
  print("NO")


Fixed code:
s = input()
s = s.replace("eraser","")
s = s.replace("erase","")
s = s.replace("dreamer","")
s = s.replace("dream","")
if len(s)==0:
    print("YES")
else:
    print("NO")
Buggy code:
s = input()
s = s[::-1]
s = s.replace('maerd','/')
s = s.replace('esare', '/')
s = s.replace('remaerd','/')
s = s.replace('resare','/')

s = s.replace('/', '')
if len(s) == 0:
    print('YES')
else:
    print('NO')

Fixed code:
s = input()
s = s[::-1]
s = s.replace('resare','/')
s = s.replace('esare', '/')
s = s.replace('remaerd','/')
s = s.replace('maerd','/')

s = s.replace('/', '')
if len(s) == 0:
    print('YES')
else:
    print('NO')
Buggy code:
s = input()

while(len(s)!=0):
    if s[-5:] == 'dream' or s[-5:] == 'erase':
        s = s[:-5]
    elif s[-6:]== 'eraser':
        s = s[:-6]
    elif s[-7:0]=='dreamer':
        s = s[:-7]
    else:
        print('N0')
        break
print('YES')
        

Fixed code:
s = input()

while(len(s)!=0):
    if s[-5:] == 'dream' or s[-5:] == 'erase':
        s = s[:-5]
    elif s[-6:]== 'eraser':
        s = s[:-6]
    elif s[-7:]=='dreamer':
        s = s[:-7]
    else:
        print('NO')
        break
else:
    print('YES')
Buggy code:
S = input()
flag = True
while(flag):
    if(len(s)==0):
        flag = False
    if s[-5:] == 'dream' or s[-5:] == 'erase':
        s = s[:-5]
    elif s[-6:]== 'eraser':
        s = s[:-6]
    elif s[-7:0]=='dreamer':
        s = s[:-7]
    else:
        break
if(flag):
    print('NO')
else:
    print('YES')
    

Fixed code:
s = input()
flag = True
while(flag):
    if(len(s)==0):
        flag = False
    if s[-5:] == 'dream' or s[-5:] == 'erase':
        s = s[:-5]
    elif s[-6:]== 'eraser':
        s = s[:-6]
    elif s[-7:]=='dreamer':
        s = s[:-7]
    else:
        break
if(flag):
    print('NO')
else:
    print('YES')
Buggy code:
s = input()
words = "eraser", "erase", "dreamer", "dream"

for word in words:
    s = s.replace(word, "")
    print(s)

print("YES" if len(s) == 0 else "NO")


Fixed code:
s = input()
words = "eraser", "erase", "dreamer", "dream"

for word in words:
    s = s.replace(word, "")

print("YES" if len(s) == 0 else "NO")
Buggy code:
s = str(input())[::-1]
while True:
    if s[:5]=="maerd" or s[:5]=="esare":
        s=s[5:]
        if len(s)==0:
            print("YES")
            exit()
    elif s[:7]=="remaerd" or s[:7]=="resare":
        s=s[7:]
        if len(s)==0:
            print("YES")
            exit()
    else:
        print("NO")
        exit()

Fixed code:
s = str(input())[::-1]
while True:
    if s[:5]=="maerd" or s[:5]=="esare":
        s=s[5:]
        if len(s)==0:
            print("YES")
            exit()
    elif s[:6]=="resare":
        s=s[6:]
        if len(s)==0:
            print("YES")
            exit()
    elif s[:7]=="remaerd":
        s=s[7:]
        if len(s)==0:
            print("YES")
            exit()
    else:
        print("NO")
        exit()
Buggy code:
import sys
s = input()
i = 0
while s[i:5] != '':
    if s[i:5] == 'dream':
        if s[i+5:i+10] == 'dream':
            i += 5
        elif s[i+5:i+10] == 'erase':
            i += 5
        elif s[i+5:i+7] == 'er':
            i += 7
        else:
            print('NO')
            sys.exit(0)
    elif s[i:5] == 'erase':
        if s[i+5:i+10] == 'dream':
            i += 5
        elif s[i+5:i+10] == 'erase':
            i += 5
        elif s[i+5:i+6] == 'r':
            i += 6
        else:
            print('NO')
            sys.exit(0)
    else:
        print('NO')
        sys.exit(0)
print('YES')

Fixed code:
import sys
s = input()
i = 0
while s[i:i+5] != '':
    if s[i:i+5] == 'dream':
        if s[i+5:i+10] == 'dream':
            i += 5
        elif s[i+5:i+10] == 'erase':
            i += 5
        elif s[i+5:i+7] == 'er':
            i += 7
        else:
            i += 5
    elif s[i:i+5] == 'erase':
        if s[i+5:i+10] == 'dream':
            i += 5
        elif s[i+5:i+10] == 'erase':
            i += 5
        elif s[i+5:i+6] == 'r':
            i += 6
        else:
            i += 5
    else:
        print('NO')
        sys.exit(0)
print('YES')
Buggy code:
import re

s = input()
ptn = re.compile(r'maerd|remaerd|sare|resare')
tmp = s[::-1]

while(True):
  res = re.match(ptn , tmp)
  if res is None:
    print(tmp)
    break
  tmp = tmp.replace(res.group(),'',1)
  print(tmp)

if len(tmp) == 0:
  print('YES')
else:
  print('NO')

Fixed code:
import re

s = input()
ptn = re.compile(r'maerd|remaerd|resare|esare')
tmp = s[::-1]

while(True):
  res = re.match(ptn , tmp)
  if res is None:
    break
  tmp = tmp.replace(res.group(),'',1)

if len(tmp) == 0:
  print('YES')
else:
  print('NO')
Buggy code:
S = input()
c = ["dream","dreamer","erase","eraser"]

S = S[::-1]
c = [cc[::-1] for cc in c]

i=0
while i < len(c):
    if S.startswith(c[i]):
        S = S[len(c[i]):]
        i = 0
        continue
    i = -~i

print("NYoe s"[S==""::2])


Fixed code:
S = input()
c = ["dream","dreamer","erase","eraser"]

S = S[::-1]
c = [cc[::-1] for cc in c]

i=0
while i < len(c):
    if S.startswith(c[i]):
        S = S[len(c[i]):]
        i = 0
        continue
    i = -~i

print("NYOE S"[S==""::2])
Buggy code:
S = list(input())
ans = 'NO'
while len(S)!=0:
    if(''.join(S[-5:])=='dream' or ''.join(S[-5:])=='erase'):
        del S[-5:]
    elif(''.join(S[-6:])==(('eraser'))):
        del S[-6:]
    elif(''.join(S[-7:])==(('dreamer'))):
        del S[-7:]
    else:
        print('else')
        break

if len(S)==0:
    ans = 'YES'

print(ans)


Fixed code:
S = list(input())
ans = 'NO'
while len(S)!=0:
    if(''.join(S[-5:])=='dream' or ''.join(S[-5:])=='erase'):
        del S[-5:]
    elif(''.join(S[-6:])==(('eraser'))):
        del S[-6:]
    elif(''.join(S[-7:])==(('dreamer'))):
        del S[-7:]
    else:
        break

if len(S)==0:
    ans = 'YES'

print(ans)
Buggy code:
S = input()
S = S[::-1]
S = S.replace('remaerd', '')
S = S.replace('resare', '')
S = S.replace('maerd', '')
S = S.replace('esare', '')
print('YES' if S == '' else 'NO')

Fixed code:
S = input()
S = S[::-1]

S = S.replace('resare', '')
S = S.replace('esare', '')
S = S.replace('remaerd', '')
S = S.replace('maerd', '')

if S:
    print('NO')
else:
    print('YES')
Buggy code:
a=["eraser","erase","dreamer","dream"]
s=input()

for i in range(4):
    s=s.replace(a[i],"")
if s="":
    print("YES")
else:
    print("NO")

Fixed code:
a=["eraser","erase","dreamer","dream"]
s=input()
 
for i in range(4):
    s=s.replace(a[i],"")
if s=="":
    print("YES")
else:
    print("NO")
Buggy code:
s=input()
s=s.replace("eraser","")
s=s.replace("erase","")
s=s.replace("dreamer","")
s=s.replace("dream","")
if len(s)==0:
    print("NO")
else:
    print("YES")

Fixed code:
s=input()
s=s.replace("eraser","")
s=s.replace("erase","")
s=s.replace("dreamer","")
s=s.replace("dream","")
if len(s)==0:
    print("YES")
else:
    print("NO")
Buggy code:
s = input()

lst = ['dream', 'dreamer', 'erase', 'eraser']
while s:
  flag = 0
  for elem in lst:
    if elem in s:
      s = s.replace(elem, '')
      flag = 1
      break
  if flag == 0:
    print('NO')
    quit()
print('YES')

Fixed code:
s = input()

lst = ['dreameraser', 'dreamerase', 'dreamer', 'dream', 'eraser', 'erase']
while s:
  flag = 0
  for elem in lst:
    if elem in s:
      s = s.replace(elem, '')
      flag = 1
      break
  if flag == 0:
    print('NO')
    quit()
print('YES')
Buggy code:
S=input()
n=len(S)
while n>0:
    print(S)
    if S[n-4:n+1]=='dream':
        n-=5
    elif S[n-4:n+1]=='erase':
        n-=5
    elif S[n-6:n+1]=='dreamer':
        n-=7
    elif S[n-5:n+1]=='eraser':
        n-=6
    else:
        print('NO')
        exit()
print('YES')

Fixed code:
S=input()
n=len(S)
while n>0:
    if S[n-5:n]=='dream':
        n-=5
    elif S[n-5:n]=='erase':
        n-=5
    elif S[n-7:n]=='dreamer':
        n-=7
    elif S[n-6:n]=='eraser':
        n-=6
    else:
        print('NO')
        exit()
print('YES')
Buggy code:
s = str(input())
l = ['dreamer', 'dream', 'eraser', 'erase']

for i in l:
  s = s.replace(i,'')

if s == "":
  print('YES')
else:
  print('NO')

Fixed code:
s = str(input())
l = ['eraser', 'erase', 'dreamer', 'dream']

for i in l:
  s = s.replace(i,'')

if s == "":
  print('YES')
else:
  print('NO')
Buggy code:
S = input()
import re
if re.match("(dream|dreamer|erase|erase)*$", S):
    print("YES")
else:
    print("NO")

Fixed code:
S = input()
import re
if re.match("(dream|dreamer|erase|eraser)*$", S):
    print("YES")
else:
    print("NO")
Buggy code:
s = str(input())
l = len(s)
s = s[::-1]
i = 0
while i < l:
    if s[i] == "r":
        if (s[i:min(l,i+7)] == "remaerd"):
            i += 7
        elif (s[i:min(l,i+6)] == "resare"):
            i += 6
        else:
            print('NO')
            break
    
    elif s[i] == "m":
        if (s[i:min(l,i+5)] == "maerd"):
            i += 5
        else:
            print('NO')
            break
            
    elif s[i] == "e":
        if (s[i:min(l,i+5)] == "esare"):
            i + 5
        else:
            print('NO')
            break
            
    else:
        print('NO')
        break
        
    
else:
    print('YES')

Fixed code:
s = str(input())
l = len(s)
s = s[::-1]
i = 0
while i < l:
    if s[i] == "r":
        if (s[i:min(l,i+7)] == "remaerd"):
            i += 7
        elif (s[i:min(l,i+6)] == "resare"):
            i += 6
        else:
            print('NO')
            break
    
    elif s[i] == "m":
        if (s[i:min(l,i+5)] == "maerd"):
            i += 5
        else:
            print('NO')
            break
            
    elif s[i] == "e":
        if (s[i:min(l,i+5)] == "esare"):
            i += 5
        else:
            print('NO')
            break
            
    else:
        print('NO')
        break
        
    
else:
    print('YES')
Buggy code:
import re
print("YES" if re.match("(dream|dreamer|erase|eraser)",input()) else "NO")

Fixed code:
import re
print("YES" if re.match("(dream|dreamer|erase|eraser)+$",input()) else "NO")
Buggy code:
s = str(input())[::-1]
print(s)
while(len(s) >= 5):
    print(s)
    if s[:5] == 'maerd':
        s = s.replace('maerd', '')
    elif s[:7] == 'remaerd':
        s = s.replace('remerd', '')
    elif s[:5] == 'esare':
        s = s.replace('esare', '')
    elif s[:6] == 'resare':
        s = s.replace('resare', '')
    else:
        print('NO')
        exit()

if len(s) == 0:
    print('YES')
else:
    print('NO')

Fixed code:
s = str(input())[::-1]

while(len(s) >= 5):
    if s[:5] == 'maerd':
        s = s.replace('maerd', '', 1)
    elif s[:7] == 'remaerd':
        s = s.replace('remaerd', '', 1)
    elif s[:5] == 'esare':
        s = s.replace('esare', '', 1)
    elif s[:6] == 'resare':
        s = s.replace('resare', '', 1)
    else:
        print('NO')
        exit()

else:
    print('YES')
Buggy code:
s=str(input())
words=["dream", "dreamer", "erase", "eraser"]

for word in words:
  s=s.replace(word,"")

if len(s)==0:
  print("YES")
else:
  print("NO")

Fixed code:
s=str(input())
words = ['eraser','erase','dreamer','dream']
for word in words:
  s=s.replace(word,'')
if len(s) == 0 :
  print('YES')
else :
  print('NO')
Buggy code:
# -*- coding:utf-8 -*-
from collections import deque

divide = ["dream", "dreamer", "erase", "eraser"];

s = input()
que = deque()

can = "NO"

que.append(0)

while(len(que) > 0):
  t = que[0]
  que.pop()
  if (t == len(s)):
    can = "YES"
    break
  for e in divide:
    if s[t:t+len(e)] == e:
      que.append(t+len(e))
print(can)

Fixed code:
# -*- coding:utf-8 -*-
from collections import deque

divide = ["dream", "dreamer", "erase", "eraser"];

s = input()
que = deque()

can = "NO"

que.append(0)

while(len(que) > 0):
  t = que.pop()
  if (t == len(s)):
    can = "YES"
    break
  for e in divide:
    if s[t:t+len(e)] == e:
      que.append(t+len(e))
print(can)