Buggy python submission (verdict: Runtime Error):
s = input()[::-1]

def solve(s):
    if s in ["maerd","remaerd","esare","resare"]:
        return True
    elif len(s) <= 7:
        return False
    if s[0:5] in ["maerd","esare"]:
        return solve(s[5:])
    if s[0:6] == "resare":
        return solve(s[6:])
    if s[0:7] == "remaerd":
        return solve(s[7:])
    return False
print("YES" if solve(s) else "NO")

Fixed submission:
s = input()[::-1]
flag = 1
i = 0
while i < len(s):
    if s[i:i+5] == "maerd" or s[i:i+5] == "esare":
        i += 5
    elif s[i:i+6] == "resare":
        i += 6
    elif s[i:i+7] == "remaerd":
        i += 7
    else:
        flag = 0
        break

print("YES" if flag else "NO")

Buggy python submission (verdict: Runtime Error):
def solve(S):
    if S in ["dream","dreamer","erase","eraser"]:
        return True
    elif len(S) <= 7:
        return False

    if S[0:7] == "dreamer":
        return solve(S[7:]) or solve(S[5:])
    elif S[0:5] == "dream":
        return solve(S[5:])
    if S[0:6] == "eraser":
        return solve(S[6:])
    elif S[0:5] == "erase":
        return solve(S[5:])

    return False

print("YES" if solve(input()) else "NO")

Fixed submission:
s = input()[::-1]
flag = 1
i = 0
while i < len(s):
    if s[i:i+5] == "maerd" or s[i:i+5] == "esare":
        i += 5
    elif s[i:i+6] == "resare":
        i += 6
    elif s[i:i+7] == "remaerd":
        i += 7
    else:
        flag = 0
        break

print("YES" if flag else "NO")

Buggy python submission (verdict: Runtime Error):
def solve(S):
    if S in ["dream","dreamer","erase","eraser"]:
        return True
    elif len(S) <= 7:
        return False

    if S[0:7] == "dreamer":
        return solve(S[7:]) or solve(S[5:])
    elif S[0:5] == "dream":
        return solve(S[5:])
    if S[0:6] == "eraser":
        return solve(S[6:]) or solve(S[5:])
    elif S[0:5] == "erase":
        return solve(S[5:])

    return False

print("YES" if solve(input()) else "NO")

Fixed submission:
s = input()[::-1]
flag = 1
i = 0
while i < len(s):
    if s[i:i+5] == "maerd" or s[i:i+5] == "esare":
        i += 5
    elif s[i:i+6] == "resare":
        i += 6
    elif s[i:i+7] == "remaerd":
        i += 7
    else:
        flag = 0
        break

print("YES" if flag else "NO")

Buggy python submission (verdict: Runtime Error):
def solve(S):
    if S == "":
        return True
    
    if S in ["dream","dreamer","erase","eraser"]:
        return True
    elif len(S) <= 6:
        return False

    if S[0:7] == "dreamer":
        return solve(S[7:]) or solve(S[5:])
    elif S[0:5] == "dream":
        return solve(S[5:])
    if S[0:6] == "eraser":
        return solve(S[6:]) or solve(S[5:])
    elif S[0:5] == "erase":
        return solve(S[5:])

    return False

print("YES" if solve(input()) else "NO")

Fixed submission:
s = input()[::-1]
flag = 1
i = 0
while i < len(s):
    if s[i:i+5] == "maerd" or s[i:i+5] == "esare":
        i += 5
    elif s[i:i+6] == "resare":
        i += 6
    elif s[i:i+7] == "remaerd":
        i += 7
    else:
        flag = 0
        break

print("YES" if flag else "NO")

Buggy python submission (verdict: Runtime Error):
def solve(S):
    if S in ["dream","dreamer","erase","eraser"]:
        return True
    elif len(S) <= 7:
        return False
    if S[0:7] == "dreamer":
        return solve(S[7:]) or solve(S[5:])
    elif S[0:5] == "dream":
        return solve(S[5:])
    if S[0:6] == "eraser":
        return solve(S[6:]) or solve(S[5:])
    elif S[0:5] == "erase":
        return solve(S[5:])

    return False

print("YES" if solve(input()) else "NO")

Fixed submission:
s = input()[::-1]
flag = 1
i = 0
while i < len(s):
    if s[i:i+5] == "maerd" or s[i:i+5] == "esare":
        i += 5
    elif s[i:i+6] == "resare":
        i += 6
    elif s[i:i+7] == "remaerd":
        i += 7
    else:
        flag = 0
        break

print("YES" if flag else "NO")