Buggy python submission (verdict: Runtime Error):
s=str(input())
st=list(s)
l=len(st)
if st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[5]=="c" and st[6]=="e":
  print("YES")
elif st[l-7]=="k" and st[l-6]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[l-6]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[5]=="c" and st[l-1]=="e":
  print("YES")
else:
  ptint("NO")

Fixed submission:
s=str(input())
st=list(s)
l=len(st)
if st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[5]=="c" and st[6]=="e":
  print("YES")
elif st[l-7]=="k" and st[l-6]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[l-6]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[5]=="c" and st[l-1]=="e":
  print("YES")
else:
  print("NO")

Buggy python submission (verdict: Runtime Error):
s=str(input())
st=list(s)
l=len(st)
if st[0]="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" st[4]=="n" and st[5]=="c" and st[6]=="e":
  print("YES")
elif st[l-7]="k" and st[l-6]=="e" and st[l-5]=="y" and st[l-4]=="e" st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]="k" and st[l-6]=="e" and st[l-5]=="y" and st[l-4]=="e" st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]="k" and st[1]=="e" and st[l-5]=="y" and st[l-4]=="e" st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]="k" and st[1]=="e" and st[2]=="y" and st[l-4]=="e" st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" st[4]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" st[4]=="n" and st[5]=="c" and st[l-1]=="e":
  print("YES")
else:
  ptint("NO")

Fixed submission:
s=str(input())
st=list(s)
l=len(st)
if st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[5]=="c" and st[6]=="e":
  print("YES")
elif st[l-7]=="k" and st[l-6]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[l-6]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[l-5]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[l-4]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[l-3]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[l-2]=="c" and st[l-1]=="e":
  print("YES")
elif st[0]=="k" and st[1]=="e" and st[2]=="y" and st[3]=="e" and st[4]=="n" and st[5]=="c" and st[l-1]=="e":
  print("YES")
else:
  print("NO")