#include <stdio.h>
#include<string.h>

int l3_write( char *b, int n);
int l3_read( char *b, int n);


int l4_write_string(char *s) {
  char a[10];
  memset(a,0,10);
  return(l3_write(a,6));
}

int l4_read_string(char *s, int max) {
  int res;
  res=l3_read(s,max);
  return(res); 
}

int l4_write_estring(char *s) {
  int i;
  char buf[1000];

  if (strlen(s)>998) {
    return(-1);
  }	

  for (i=0;i<strlen(s);i++) {
    buf[i] = s[i] ^ 0x55;
  }
  buf[i]=0;

  return(l3_write(buf,strlen(s)+1));

}

int l4_read_estring(char *s, int max) {
  int i;
  int len;
  char buf[1000];


  len = l3_read(buf,1000);

  if (len>max) return(-1);

  if (buf[len-1]!=0) return(-1);

  for (i=0;i<len-1;i++) {
    s[i] = buf[i]^0x55;
  }

  s[len]=0;

  return(len);

}