int string2int(string thestring) {
  int result = 0;

  for(int i=0; i<thestring.length(); i++)
    if(thestring[i] >= '0' && thestring[i] <= '9')
      result = (result * 10) + (thestring[i] - '0');

  if(thestring[0] == '-')
    result = 0 - result;

  return result;
}