Unsigned Char & Signed Char - C/C++

#include <stdio.h>

#include <conio.h>

Unsigned char   a,b,c;

Signed char       x,y,z;

main(void)

        {                                

a=x =79;

b=y=84;

c=a+b; z=y+x;

clrscr();

printf("Nilai C adalah :  %d\n",c);

printf("Nilai Z adalah :  %d\n",z);

getch();                          

return 0;

}