#include <iostream>
#include <string>
using std::cout;
using std::cin;
using std::string;
string encryptcharacter {"~"};

string encrypt(string buffer)
{

    for(int i=0; i<(int)buffer.size(); i++) {
        if (i%2==0) {
            buffer[i]+=3;
        }
        if (i%3==0) {
            buffer[i]+=2;
        } else {
            buffer[i]+=1;
        }

    }


    buffer.insert(0,encryptcharacter);
    return buffer;
}

string decrypt(string buffer)
{

    buffer.erase(buffer.begin());

    for(int i=0; i<(int)buffer.size(); i++) {

        if (i%2==0) {
            buffer[i]-=3;
        }
        if (i%3==0) {
            buffer[i]-=2;
        } else {
            buffer[i]-=1;
        }
    }

    return buffer;
}

int main()
{

    string buffer;
    cout<<"Encrypter/Decrypter V1.5 by Baho and biNS. ETF 2016"<<std::endl;

    while(true) {



        getline(cin,buffer);

        if(buffer[0]==encryptcharacter[0]) {
            //decrypt(buffer);
            buffer=decrypt(buffer);
            cout<<buffer<<std::endl;
        } else if(buffer.size()!=0) {
            //encrypt(buffer);
            buffer=encrypt(buffer);
            cout<<buffer<<std::endl;
        } else {
            cout<<"Greska, prazan string"<<std::endl;
        }

    }



    return 0;
}