#include<stdio.h>
#include<ctype.h>

int main(int argc, char ** argv){
	if(argc < 2){
		printf("No string specified!\n");
		return 1;
	}

	char *string = argv[1];
	for(unsigned char *c = string; *c; c++){
		if(islower(*c)){
			*c += 13;
			if(*c > 'z')
				*c -= 26;
		} else if(isupper(*c)){
			*c += 13;
			if(*c > 'Z')
				*c -= 26;
		}
		printf("c = %lx, *c = %c, *c also = %d\n", c, *c, *c);
	}
	puts(string);
	return 0;
}