/*
 *a program using the function getchar() that inputs a string of
 *characters.  It then encrypts the string using the following code: 'b' becomes
 *'a', 'c' becomes 'b', ..., 'a' becomes 'z', 'B' becomes 'A', 'C' becomes 'B',
 *..., 'A' becomes 'Z'
 *author:rahule@cse.iitk.ac.in
*/
#include <stdio.h>

int main()
{
int c;
	printf("Enter the string\n");
	while((c=getchar())!='\n')	//reads charecters till the newline character
	{
		if(((c>65)&&(c<91))||((c>97)&&(c<123)))		//checks whether the entered character is a valid alphebet
			putchar(c-1);
		else if((c==65)||(c==97))		//if character is "a" or "A",prints "z" and "Z" respectively.
			putchar(c+25);		
	}
	printf("\n");
}