def reverse(string):
begin=0
end=len(string)-1
strlist= [i for i in string]
while(begin<end):
temp=strlist[begin]
strlist [begin]=strlist[end]
strlist[end]=temp
begin+=1
end-=1
return''.join(strlist)
print reverse("flash")
ZGVmIHJldmVyc2Uoc3RyaW5nKToKCWJlZ2luPTAKCWVuZD1sZW4oc3RyaW5nKS0xCglzdHJsaXN0PSBbaSBmb3IgaSBpbiBzdHJpbmddCgl3aGlsZShiZWdpbjxlbmQpOgoJCXRlbXA9c3RybGlzdFtiZWdpbl0KCQlzdHJsaXN0IFtiZWdpbl09c3RybGlzdFtlbmRdCgkJc3RybGlzdFtlbmRdPXRlbXAKCQliZWdpbis9MQoJCWVuZC09MQoJCXJldHVybicnLmpvaW4oc3RybGlzdCkKCQlwcmludCByZXZlcnNlKCJmbGFzaCIp