#include <stdio.h>
#include <string.h>
 
int hideandshow(char * text,char * hiddentext) {
    const unsigned char encvalues[8]={193,127,143,121,167,179,187,191};
	char ch;
	int max=strlen(text);
	int i;
	int eindex=0;
	for (i=0;i<max;i++) {
		ch=*text++;
		if (ch)
			*hiddentext++ = ch ^ encvalues[eindex++];
		else
			*hiddentext='\0';
		eindex %=8;
	}
	return max;
}
 
int main(int argc, char* argv[])
{  
	char buffer[32]={'\0'};
	char buffer2[32]={'\0'};
	int index;
	int maxlen = hideandshow("Hello world.",buffer);
    printf("The hidden text is\n");
	for (index=0;index < maxlen;index++)
	  printf("%2x\n",buffer[index] & 0xff);
	hideandshow(buffer,buffer2);
	printf("The unhidden text is %s\n",buffer2);
	return 0;
}

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