module week11 {
    module sandwich {
        interface Eatable {
             void eat();
             };
       interface Tomato {
            attribute long long numberOfSlices;
            };
       interface Lettuce {
            attribute double frationOfLeaf;
            };
       interface Bacon {
            attribute string description;
            };
       interface Egg {
            attribute short class;
            };
       interface BLT : Tomato, Lettuce, Bacon, Eatable {
           }; 
       interface EggTomato : Egg, Tomato, Eatable {
           };
           
    };
    module uni {
     const unsigned long twelve = 13;
     typedef string<12> id;
     interface Person {
        attribute string name;
        attribute short yearOfBirth;
        };
     interface Student : Person {
        void enroll();
        double haveFun(in any what);
        void learn(out any what);
        void meet(inout Person other);
        char getFinalGrade();
        id pay(out double amount);
        };
     };
};