C :

#include<stdio.h>
#include<string.h>
int main()
{
	char s1[100],s2[100];
	int i,l;
	scanf("%s",s1);
	l=strlen(s1);
	for(i=0;i<l;i++)
	{
		if((s1[i]>='a'&&s1[i]<'w')||(s1[i]>='A'&&s1[i]<'W'))
		{
			s1[i]=s1[i]+4;
		}
		else s1[i]=s1[i]-22;
	}
	printf("%s\n",s1);
}

C++ :

#include<iostream>
#include<cstdio>
#include<iostream>

using namespace std;

int main(){
    string str;
    while(cin>>str){
        for(int i=0;i<str.length();i++)
            if(str[i]>='W'&&str[i]<='Z'||str[i]>='w'&&str[i]<='z')
                printf("%c",str[i]-22);
            else
                printf("%c",str[i]+4);
        cout<<endl;
    }
    return 0;
}