ROT13-2013-prva parc.

#include <iostream>
#include <string>

using namespace std;

void ROT13 (string &s) {
    int razlika;
for (int i=0; i<s.length(); i++) {
    if (s[i]>='A' && s[i]<='M' || s[i]>='a' && s[i]<='m') {
        razlika='N'-'A';
        s[i]+=razlika;
    }
    else if (s[i]>='N' && s[i]<='Z' || s[i]>='n' && s[i]<='z')
        s[i]-=razlika;

}}

 int main() {
 string s{"HELLO"};
 ROT13(s);
 for (int i=0; i<s.length(); i++) cout<<s[i];
 return 0;
 }