#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define OFFSET 4
int main(int argc, char *argv[])
{
	char curr, cnew;
	if (argc != 2)
	{
		printf("Error: usage %s string_to_convert\n", argv[0]);
		exit(1);
	}
	printf("String to be converted:\n%s\n", argv[1]);
	printf("String after conversion:%d\n", (int)strlen(argv[1]));
	for (int i = 0; i < strlen(argv[1]); i++)
	{
		curr = argv[1][i];
		if (curr >= 'A' && curr <= 'Z')
		{
			cnew = curr + OFFSET;
			if (cnew > 'Z')
			{
				cnew = cnew - 'Z' + 'a' - 1;
			}
			printf("%c", cnew);
		}
		else if (curr >= 'a' && curr <= 'z')
		{
			cnew = curr + OFFSET;
			if (cnew > 'z')
			{
				cnew = 'A' + (cnew - 'z' - 1);
			}
			printf("%c", cnew);
		}
		else
		{
			printf("%c", curr);
		}
	}
	printf("\n");
	exit(0);
}