string itoa(int i)
{
  int rem = 0;
  string ret;
  while(0 < i)
  {
    rem = i%10;
    i = i/10;
    ret = (char)(rem + '0') + ret;
  }
  return ret;
}

string itoa(int i)
{
  int rem = 0;
  string ret;
  while(0 < i)
  {
    rem = i%10;
    i = i/10;
    ret = (char)(rem + '0') + ret;
  }
  return ret;
}