qyliang/CodeNanoFix huggingface dataset:
Buggy code:
S = input()

start = 0

while start < len(S):
    print(start)
    if start == len(S)-8 or start > len(S)-5:
        print("NO")
        exit()
    elif start == len(S)-7 and S[start:start+7] == "dreamer":
        print("YES")
        exit()
    elif start == len(S)-6 and S[start:start+6] == "eraser":
        print("YES")
        exit()
    elif start == len(S)-5 and S[start:start+5] == "erase":
        print("YES")
        exit()
    elif start == len(S)-5 and S[start:start+5] == "dream":
        print("YES")
        exit()
    elif S[start:start+6] == "eraser":
        start +=6
    elif S[start:start+5] == "erase":
        start +=5
    elif S[start:start+8] == "dreamera":
        start +=5
    elif S[start:start+7] == "dreamer":
        start +=7
    elif S[start:start+5] == "dream":
        start +=5
    else:
        print("NO")
        exit()
print("YES")

Fixed code:
S = input()

start = 0

while start < len(S):

    if start == len(S)-8 or start > len(S)-5:
        print("NO")
        exit()
    elif start == len(S)-7 and S[start:start+7] == "dreamer":
        print("YES")
        exit()
    elif start == len(S)-6 and S[start:start+6] == "eraser":
        print("YES")
        exit()
    elif start == len(S)-5 and S[start:start+5] == "erase":
        print("YES")
        exit()
    elif start == len(S)-5 and S[start:start+5] == "dream":
        print("YES")
        exit()
    elif S[start:start+6] == "eraser":
        start +=6
    elif S[start:start+5] == "erase":
        start +=5
    elif S[start:start+8] == "dreamera":
        start +=5
    elif S[start:start+7] == "dreamer":
        start +=7
    elif S[start:start+5] == "dream":
        start +=5
    else:
        print("NO")
        exit()
print("YES")
Buggy code:
# -*- coding: utf-8 -*-

def check(string):
    if string[-5:] == "dream":
        new = string[:-5]
        return new

    if string[-7:] == "dreamer":
        new = string[:-7]
        return new

    if string[-5:] == "erase":
        new = string[:-5]
        return new

    if string[-6:] == "eraser":
        new = string[:-6]
        return new

    print("NO")


if __name__ == '__main__':
    s = str(input())

    while s:
        print(s)
        s = check(s)

    if s == "":
        print("YES")


Fixed code:
# -*- coding: utf-8 -*-

def check(string):
    if string[-5:] == "dream":
        new = string[:-5]
        return new

    if string[-7:] == "dreamer":
        new = string[:-7]
        return new

    if string[-5:] == "erase":
        new = string[:-5]
        return new

    if string[-6:] == "eraser":
        new = string[:-6]
        return new

    print("NO")


if __name__ == '__main__':
    s = str(input())

    while s:
        s = check(s)

    if s == "":
        print("YES")
Buggy code:
s = input()
t = ''
add_list = ['dream', 'dreamer', 'erase', 'eraser']
cur = len(s)
for i in range(len(s)):
    if s[-1 - i:cur] in add_list:
        cur = i
if cur == len(s) - 1:
    print('YES')
else:
    print('No')

Fixed code:
s = input()
t = ''
add_list = ['dream', 'dreamer', 'erase', 'eraser']
cur = len(s)
for i in range(len(s)):
    if s[-1 - i:cur] in add_list:
        cur = -1 - i
if -cur == len(s):
    print('YES')
else:
    print('NO')
Buggy code:
s = input()
if s.replace('eraser','').replace('erase','').replace('dreamer','').replace('dream','')
:
    print('NO')
else:
    print('YES')

Fixed code:
s = input().replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("dream", "")
if s:
  print("NO")
else:
  print("YES")
Buggy code:
s = input()
n = len(s)
i = 0
flag = 0
while(True):
    if(s[i:i+5]) == "dream":
        if(i+5==n):
            break
        elif(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
            if(i==n):
                break
        else:
            flag = 1
            break

    elif(s[i:i+5]) == "erase":
        if(i+5==n):
            break
        elif(s[i+5:i+10] =="dream"):
            i += 5
        elif(s[i+5:i+10] == "erase"):
            i += 5
        elif(s[i+4:i+6] == "er"):
            i += 7
            if(i==n):
                break
        else:
            flag = 1
            break
    else:
        flag = 1
        break
print("YES" if flag == 0 else "NO")

Fixed code:
s = input()
n = len(s)
i = 0
flag = 0
while(True):
    if(s[i:i+5]) == "dream":
        if(i+5==n):
            break
        elif(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
            if(i==n):
                break
        else:
            flag = 1
            break

    elif(s[i:i+5]) == "erase":
        if(i+5==n):
            break
        elif(s[i+5:i+10] =="dream"):
            i += 5
        elif(s[i+5:i+10] == "erase"):
            i += 5
        elif(s[i+4:i+6] == "er"):
            i += 6
            if(i==n):
                break
        else:
            flag = 1
            break
    else:
        flag = 1
        break
print("YES" if flag == 0 else "NO")
Buggy code:
import re
S = input()
num = []
l = []


if ("eraser" in S)  == True:
	S.replace("eraser", "")

if ("erase" in S)   == True:
	S.replace("erase", "")

if ("dreamer" in S) == True:
	S.replace("dreamer", "")

if ("dream" in S)   == True:
	S.replace("dreamer", "")

"""
if ("eraser" in S)  == True:
	num.append(S.count("eraser"))
	for i in range(S.count("eraser")):
		a.append(S.find("eraser"))
		S[S.find("eraser"):6]

if ("erase" in S)   == True:
	num.append(S.count("erase"))
	for i in range(S.count("erase")):
		a.append(S.find("erase"))
		S[S.find("erase"):5]

if ("dreamer" in S) == True:
	num.append(S.count("dreamer"))
	for i in range(S.count("dreamer")):
		a.append(S.find("dreamer"))
		S[S.find("dreamer"):7]

if ("dream" in S)   == True:
	num.append(S.count("dream"))
	for i in range(S.count("dream")):
		a.append(S.find("dream"))
		S[S.find("dream"):5]
"""
if len(S) == 0:
	print("YES")

if len(S) != 0:
	print("NO")



Fixed code:
import re
S = input()
num = []
l = []

answer = S.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("dream", "")
if len(answer) == 0:
	print("YES")
else:
	print("NO")



"""
if ("eraser" in S)  == True:
	S.replace("eraser", "")

if ("erase" in S)   == True:
	S.replace("erase", "")

if ("dreamer" in S) == True:
	S.replace("dreamer", "")

if ("dream" in S)   == True:
	S.replace("dreamer", "")
"""

"""
if ("eraser" in S)  == True:
	num.append(S.count("eraser"))
	for i in range(S.count("eraser")):
		a.append(S.find("eraser"))
		S[S.find("eraser"):6]

if ("erase" in S)   == True:
	num.append(S.count("erase"))
	for i in range(S.count("erase")):
		a.append(S.find("erase"))
		S[S.find("erase"):5]

if ("dreamer" in S) == True:
	num.append(S.count("dreamer"))
	for i in range(S.count("dreamer")):
		a.append(S.find("dreamer"))
		S[S.find("dreamer"):7]

if ("dream" in S)   == True:
	num.append(S.count("dream"))
	for i in range(S.count("dream")):
		a.append(S.find("dream"))
		S[S.find("dream"):5]
"""
Buggy code:
#049 C

S = input()
A = 'dream'
B = 'dreamer'
C = 'erase'
D = 'eraser'

S=S[::-1]
A=A[::-1]
B=B[::-1]
C=C[::-1]
D=D[::-1]

tmp =""
for i in S:
    tmp +=i
    print(tmp)
    for j in [A,B,C,D]:
        if tmp == j:
            S=S.replace(tmp,"",1)
            print(S)
            tmp=""
if len(S)==0:
    print('YES')
else:
    print('NO')

Fixed code:
#049 C

S = input()
A = 'dream'
B = 'dreamer'
C = 'erase'
D = 'eraser'

S=S[::-1]
A=A[::-1]
B=B[::-1]
C=C[::-1]
D=D[::-1]

tmp =""
for i in S:
    tmp +=i
    for j in [A,B,C,D]:
        if tmp == j:
            S=S.replace(tmp,"",1)
            tmp=""
if len(S)==0:
    print('YES')
else:
    print('NO')
Buggy code:
s = input()
for word in ["eraser","erase","dreamer","dream"]:
    s = s.replace(word,".")
    if len(set(s)) == 1:
        print("YES")
    else:
        print("NO")

Fixed code:
s = input()
for word in ["eraser","erase","dreamer","dream"]:
    s = s.replace(word,".")
if len(set(s)) == 1:
    print("YES")
else:
    print("NO")
Buggy code:
import sys
import math
import numpy as np
import copy

def main():
    s = input()

    a, b, c, d = "dream", "dreamer", "erase", "eraser"
    ra, rb, rc, rd = a[::-1], b[::-1], c[::-1], d[::-1]
    rs = s[::-1]

    while rs:
        flag = False
        for ele in [ra, rb, rc, rd]:
            if rs.startswith(ele):
                rs = rs.replace(ele, "", 1)
                flag = True
        if not flag:
            print("No")
            return 0
    
    print("Yes")
    return 0

if __name__ == '__main__':
    sys.exit(main())

Fixed code:
import sys
import math
import numpy as np
import copy

def main():
    s = input()

    a, b, c, d = "dream", "dreamer", "erase", "eraser"
    ra, rb, rc, rd = a[::-1], b[::-1], c[::-1], d[::-1]
    rs = s[::-1]

    while rs:
        flag = False
        for ele in [ra, rb, rc, rd]:
            if rs.startswith(ele):
                rs = rs.replace(ele, "", 1)
                flag = True
        if not flag:
            print("NO")
            return 0
    
    print("YES")
    return 0

if __name__ == '__main__':
    sys.exit(main())
Buggy code:
#C - Day dream
S_input = input()
S = S_input
for i in range(len(S_input)):
    S = S[:i]+S_input[len(S_input)-1-i]+S[i+1:]
#print(S)
#S_input = input()
    
#S = S_input[::-1]
end_flg = 1
while end_flg:
    if S.startswith('maerd'):
        S = S.replace('maerd', '', 1)
    elif S.startswith('remaerd'):
        S = S.reaplace('remaerd','',1)
    elif S.startswith('esare'):
        S = S.replace('esare','',1)
    elif S.startswith('resare'):
        S = S.replace('resare', '', 1)
    else:
        end_flg = 0
if len(S_input) == 0:
    print('YES')
else:
    print('NO')


Fixed code:
#C - Day dream
S_input = input()
S = S_input
for i in range(len(S_input)):
    S = S[:i]+S_input[len(S_input)-1-i]+S[i+1:]
#print(S)
#S_input = input()
    
#S = S_input[::-1]
end_flg = 1
while end_flg:
    if S.startswith('maerd'):
        S = S.replace('maerd', '', 1)
    elif S.startswith('remaerd'):
        S = S.replace('remaerd','',1)
    elif S.startswith('esare'):
        S = S.replace('esare','',1)
    elif S.startswith('resare'):
        S = S.replace('resare', '', 1)
    else:
        end_flg = 0
if len(S) == 0:
    print('YES')
else:
    print('NO')
Buggy code:
# sys.stdin.readline
import sys

input = sys.stdin.readline


class AtCoder:
    def main(self):
        S = input().rstrip()

        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')
                exit()
        print('YES')


# Run main
if __name__ == '__main__':
    AtCoder().main()


Fixed code:
# sys.stdin.readline
import sys

input = sys.stdin.readline


class AtCoder:
    def main(self):
        S = input().rstrip()

        while len(S) > 0:
            if S[:11] == 'dreameraser':
                S = S[11:]
            elif S[:10] == 'dreamerase':
                S = S[10:]
            elif S[:7] == 'dreamer':
                S = S[7:]
            elif S[:6] == 'eraser':
                S = S[6:]
            elif S[:5] == 'dream' or S[:5] == 'erase':
                S = S[5:]
            else:
                print('NO')
                exit()
        print('YES')


# Run main
if __name__ == '__main__':
    AtCoder().main()
Buggy code:
S = input()

S = S.replace("dreamer", "")
S = S.replace("eraser", "")
S = S.replace("dream", "")
S = S.replace("erase", "")

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 S=="":
    print("YES")
else:
    print("NO")
Buggy code:
import copy
def deleteStr(S, text):
    if len(S) < len(text):
        return S
    for i, letter in enumerate(text):
        if letter == S[i]:
            continue
        else:
            return S
    return S[len(text):]

def checkStr(S, text):
    if len(S) < len(text):
        return False
    for i, letter in enumerate(text):
        if letter == S[i]:
            continue
        else:
            return False
    return True

def main():
    S = input()

    for i in range(len(S)):
        S_len = len(S)
        if checkStr(S, 'dreamer'):
            if checkStr(S, 'dreamerase'):
                S = deleteStr(S, 'dream')
            else:
                S = deleteStr(S, 'dreamer')
        else:
            S = deleteStr(S, 'dream')

        if checkStr(S, 'eraser'):
            S = deleteStr(S, 'eraser')
        else:
            S = deleteStr(S, 'erase')

        if S_len == len(S):
            if S_len == 0:
                print('Yes')
            else:
                print('No')
            break


if __name__ == '__main__':
    main()

Fixed code:
import copy
def deleteStr(S, text):
    if len(S) < len(text):
        return S
    for i, letter in enumerate(text):
        if letter == S[i]:
            continue
        else:
            return S
    return S[len(text):]

def checkStr(S, text):
    if len(S) < len(text):
        return False
    for i, letter in enumerate(text):
        if letter == S[i]:
            continue
        else:
            return False
    return True

def main():
    S = input()

    for i in range(len(S)):
        S_len = len(S)
        if checkStr(S, 'dreamer'):
            if checkStr(S, 'dreamerase'):
                S = deleteStr(S, 'dream')
            else:
                S = deleteStr(S, 'dreamer')
        else:
            S = deleteStr(S, 'dream')

        if checkStr(S, 'eraser'):
            S = deleteStr(S, 'eraser')
        else:
            S = deleteStr(S, 'erase')

        if S_len == len(S):
            if S_len == 0:
                print('YES')
            else:
                print('NO')
            break


if __name__ == '__main__':
    main()
Buggy code:
def main():
    s = input()
    dream = 0
    erase = 1
    work = []
    temp1 = 0
    temp2 = 0
    kind = -1
    append = work.append
    for c in s:
        if c == 'd':
            if kind != -1:
                append([kind, temp2-temp1])
            kind = dream
            temp1 = temp2
        elif c == 's':
            if kind != -1:
                append([kind, temp2-temp1-3])
            kind = erase
            temp1 = temp2-3
        temp2 += 1
    append([kind, len(s)-temp1])
    result = []
    append = result.append
    for i, j in work:
        if i == dream:
            if j <= 5:
                append("dream")
            else:
                append("dreamer")
        else:
            if j <= 5:
                append("erase")
            else:
                append("eraser")
    result = "Yes" if "".join(result)==s else "No"
    print(result)
main()

Fixed code:
def main():
    s = input()
    dream = 0
    erase = 1
    work = []
    temp1 = 0
    temp2 = 0
    kind = -1
    append = work.append
    for c in s:
        if c == 'd':
            if kind != -1:
                append([kind, temp2-temp1])
            kind = dream
            temp1 = temp2
        elif c == 's':
            if kind != -1:
                append([kind, temp2-temp1-3])
            kind = erase
            temp1 = temp2-3
        temp2 += 1
    append([kind, len(s)-temp1])
    result = []
    append = result.append
    for i, j in work:
        if i == dream:
            if j <= 5:
                append("dream")
            else:
                append("dreamer")
        else:
            if j <= 5:
                append("erase")
            else:
                append("eraser")
    result = "YES" if "".join(result)==s else "NO"
    print(result)
main()
Buggy code:
l=list(input())
a=[list('dream'),list('erase')]
b=[list('dreamer'),list('eraser')]
n=len(l)
r=0
while n<=4:
    f=0
    if n>=6:
        if l[len(l)-5:] in a:
            l[len(l)-5:]=[]
            n-=5
            f+=1
        if l[len(l)-6:] in b:
            l[len(l)-6:]=[]
            n-=6
            f+=1
    elif n>=5:
        if l[len(l)-5:] in a:
            l[len(l)-5:]=[]
            n-=5
            f+=1
    if f==0:
        r=1
        break
if r==1 or n>0:
    print('NO')
else:
    print('YES')

Fixed code:
l=list(input())
a=[list('dream'),list('erase')]
b=[list('eraser')]
c=[list('dreamer')]
n=len(l)
r=0
while n>=5:
    f=0
    if n>=7:
        if l[len(l)-5:] in a:
            l[len(l)-5:]=[]
            n-=5
            f+=1
        if l[len(l)-6:] in b:
            l[len(l)-6:]=[]
            n-=6
            f+=1
        if l[len(l)-7:] in c:
            l[len(l)-7:]=[]
            n-=7
            f+=1
    elif n>=6:
        if l[len(l)-5:] in a:
            l[len(l)-5:]=[]
            n-=5
            f+=1
        if l[len(l)-6:] in b:
            l[len(l)-6:]=[]
            n-=6
            f+=1
    elif n>=5:
        if l[len(l)-5:] in a:
            l[len(l)-5:]=[]
            n-=5
            f+=1
    if f==0:
        r=1
        break
if r==1 or n>0:
    print('NO')
else:
    print('YES')
Buggy code:

def main():
    S = input()
    while True:
        if S[:7] == "dreamer":
            S = S[7:]
        elif S[:6] == "eraser":
            S = S[6:]
        elif S[:5] == "erase":
            S = S[5:]
        elif S[:5] == "dream":
            S = S[5:]
        else:
            print("NO")
            break

        if len(S) == 0:
            print("YES")
            break


if __name__ == "__main__":
    main()


Fixed code:

def main():
    S = input()
    while True:
        if S[-7:] == "dreamer":
            S = S[:-7]
        elif S[-6:] == "eraser":
            S = S[:-6]
        elif S[-5:] == "erase":
            S = S[:-5]
        elif S[-5:] == "dream":
            S = S[:-5]
        else:
            print("NO")
            break

        if len(S) == 0:
            print("YES")
            break


if __name__ == "__main__":
    main()
Buggy code:
S=input()[::-1]
num=(len(S)//5)+1
while num > 0:
  for i in ['dream'[::-1], 'dreamer'[::-1], 'erase'[::-1], 'eraser'[::-1]]:
    if S[:len(i)] == i:
      S = S[len(i):]
    if S == '':
      print('YES')
      exit()
  num -= 1
print('No')

Fixed code:
S=input()[::-1]
num=(len(S)//5)+1
while num > 0:
  for i in ['dream'[::-1], 'dreamer'[::-1], 'erase'[::-1], 'eraser'[::-1]]:
    if S[:len(i)] == i:
      S = S[len(i):]
    if S == '':
      print('YES')
      exit()
  num -= 1
print('NO')
Buggy code:
S=input()

S.replace('eraser','')
S.replace('erase','')
S.replace('dreamer','')
S.replace('dream','')

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()
i=1
while i<len(s)+1:
	if s[-i:-i-5:-1]=="erase" \
	or s[-i:-i-5:-1]=="dream":
		print(s[-i:-i-5:-1])
		i+=5
	elif s[-i:-i-6:-1]=="eraser":
		i+=6
	elif s[-i:-i-7:-1]=="deaamer":
		i+=7
	else:
		print("NO")
		exit()
print("YES")


Fixed code:
s=input()
i=1
while i<len(s):
	if s[-i-4:-i]+s[-i]=="erase" \
	or s[-i-4:-i]+s[-i]=="dream":
		i+=5
	elif s[-i-5:-i]+s[-i]=="eraser":
		i+=6
	elif s[-i-6:-i]+s[-i]=="dreamer":
		i+=7
	else:
		print("NO")
		exit()
print("YES")
Buggy code:
int_s = input()
str_sr = int_s[::-1]


str_a = ['dream', 'dreamer', 'erase', 'eraser']

str_r = list(map(lambda x: x[::-1], str_a))

result = True

while len(str_sr):
    currnt_flg = False
    for r in str_r:
        print('r:' + r)
        if len(str_sr) >= len(r) and str_sr[:len(r)] == r:
            print('ok')
            str_sr = str_sr[len(r):]
            print(str_sr)
            current_flg = True
            break
    else:
        result = False
        break

if result:
    print('YES')
else:
    print('No')

Fixed code:
int_s = input()
str_sr = int_s[::-1]


str_a = ['dream', 'dreamer', 'erase', 'eraser']

str_r = list(map(lambda x: x[::-1], str_a))

result = True

while len(str_sr):
    currnt_flg = False
    for r in str_r:
        # print('r:' + r)
        if len(str_sr) >= len(r) and str_sr[:len(r)] == r:
            # print('ok')
            str_sr = str_sr[len(r):]
            # print(str_sr)
            current_flg = True
            break
    else:
        result = False
        break

if result:
    print('YES')
else:
    print('NO')
Buggy code:

def judge(S):
    cursor = 0
    len_S = len(S)
    while cursor < len_S:
        next_str = S[cursor:cursor+8]
        if next_str[:] == "dreamera":
            cursor += 5
        elif next_str[:7] == "dreamer":
            cursor += 7
        elif next_str[:6] == "eraser":
            cursor += 6
        elif next_str[:5] == ("dream" or "erase"):
            cursor += 5
        else:
            return False
        
    if cursor != len_S:
        return False
    
    return True


S = input()

if judge(S):
    print("YES")
else:
    print("NO")

Fixed code:
def judge(S):
    cursor = 0
    len_S = len(S)
    
    while cursor < len_S:
        next_str = S[cursor:cursor+8]
        if next_str[:] == "dreamera":
            cursor += 5
        elif next_str[:7] == "dreamer":
            cursor += 7
        elif next_str[:6] == "eraser":
            cursor += 6
        elif (next_str[:5] == "dream") or (next_str[:5] == "erase"):
            cursor += 5
        else:
            return False
        
    if cursor != len_S:
        return False
    
    return True

S = input()

if judge(S):
    print("YES")
else:
    print("NO")
Buggy code:
string = input()

flg = True
while len(string) > 0:
  if string.endswith('dream'):
    string = string[:-5]
  elif string.endswith('dreamer'):
    string = string[:-7]
  elif string.endswith('erase'):
    string = string[:-6]
  elif string.endswith('eraser'):
    string = string[:-6]
  else:
    print('NO')
    flg = False
if flg:
  print('YES')

Fixed code:
string = input()
 
flg = True
while len(string) > 0:
  if string.endswith('dream'):
    string = string[:-5]
  elif string.endswith('dreamer'):
    string = string[:-7]
  elif string.endswith('erase'):
    string = string[:-5]
  elif string.endswith('eraser'):
    string = string[:-6]
  else:
    print('NO')
    flg = False
    break
if flg:
  print('YES')
Buggy code:
s = input().replace("dream","").replace("dreamer","").replace("erase","").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]

L = ['dream', 'dreamer', 'erase', 'eraser']
L = [l[::-1] for l in L]

can = True
ind = 0
S_max = len(S)

while can:
    
    # print(ind)
    if ind == S_max:
        break

    for l in L:
        if ind + len(l) > S_max:
            pass
        else:
    #        print(S[ind: ind+len(l)])
            if l == S[ind: ind+len(l)]:
                ind += len(l)
    #             print(1)
                break
    else:
    #     print(2)
        can = False

if can:
    print("Yes")
else:
    print("No")


Fixed code:
S = input()

S = S[::-1]

L = ['dream', 'dreamer', 'erase', 'eraser']
L = [l[::-1] for l in L]

can = True
ind = 0
S_max = len(S)

while can:
    
    # print(ind)
    if ind == S_max:
        break

    for l in L:
        if ind + len(l) > S_max:
            pass
        else:
    #        print(S[ind: ind+len(l)])
            if l == S[ind: ind+len(l)]:
                ind += len(l)
    #             print(1)
                break
    else:
    #     print(2)
        can = False

if can:
    print("YES")
else:
    print("NO")
Buggy code:
S = input()
T = ["dreamer", "dream", "eraser", "erase"]
def daydream(S, T):
    for word in T:
        S = S.replace(word, " ")
    return "YES" if len(S.replace(" ", "")) == 0 else "NO"

print(daydream(S, T))

Fixed code:
S = input()
T = ["eraser", "erase", "dreamer", "dream"]
def daydream(S, T):
    for word in T:
        S = S.replace(word, " ")
    return "YES" if len(S.replace(" ", "")) == 0 else "NO"
 
print(daydream(S, T))