diff --git a/contracts/PetPark.sol b/contracts/PetPark.sol
index d53e90d..022b486 100644
--- a/contracts/PetPark.sol
+++ b/contracts/PetPark.sol
@@ -4,4 +4,101 @@ pragma solidity ^0.8.0;
 
 contract PetPark {
 
-}
\ No newline at end of file
+enum animalType {None, Fish, Cat, Dog, Rabbit, Parrot}
+enum gender {Male, Female}
+address immutable owner;
+
+struct member{
+    gender _gender;
+    uint age;
+    address memberAddress;
+}
+mapping (animalType => uint) numberOfAnimals;
+mapping (address => animalType) borrowed;
+mapping (address => member) members;
+
+event Added (animalType, uint);
+event Borrowed (animalType);
+event Returned (animalType);
+
+constructor (){
+  owner = msg.sender;
+}
+
+function add (animalType _animalType, uint _count) public{
+    require (owner == msg.sender, "Not an owner");
+    require ( _animalType != animalType.None, "Invalid animal");
+    numberOfAnimals[_animalType] += _count;
+    emit Added(_animalType, numberOfAnimals[_animalType]);
+}
+
+function animalCounts(animalType _animalType) public view returns (uint) {
+  return numberOfAnimals[_animalType];
+}
+
+
+function borrow (uint _age, gender _gender, animalType _animalType) public{
+    //basic checks
+    require ( _age> 0, "Invalid Age");
+    require (_animalType != animalType.None, "Invalid animal type");
+    require (numberOfAnimals[_animalType] > 0, "Selected animal not available");
+
+
+    // borrower age and gender consistency check
+    member memory newMemberAdress = members [msg.sender];
+    if (newMemberAdress.memberAddress == address(0)){
+        // add a member
+        members[msg.sender] = member(_gender, _age, msg.sender);
+    }
+    else{
+        // check client information
+        require (newMemberAdress.age == _age, "Invalid Age");
+        require (newMemberAdress._gender == _gender, "Invalid Gender");
+    }
+
+    // check if the address already has a animal
+    animalType  _currentpet = borrowed[msg.sender];
+    require (_currentpet == animalType.None, "Already adopted a pet");
+
+    // borrow logic with conditions defined in Problem statement
+    if(_gender == gender.Male){
+        if (_animalType == animalType.Dog || _animalType == animalType.Fish){
+            borrowed[msg.sender] = _animalType;
+            numberOfAnimals [_animalType] -= 1;
+            emit Borrowed(_animalType);
+        }
+        else{
+          revert("Invalid animal for men");
+        }
+    }
+
+    else if (_gender == gender.Female){
+        if (_animalType == animalType.Cat){
+            if (_age >= 40){
+                borrowed[msg.sender] = _animalType;
+                numberOfAnimals [_animalType] -= 1;
+                emit Borrowed(_animalType);
+            }
+            else {
+                revert("Invalid animal for women under 40");
+            }
+        }
+        else{
+                borrowed[msg.sender] = _animalType;
+                numberOfAnimals [_animalType] -= 1;
+                emit Borrowed(_animalType);
+        }
+    }
+}
+
+
+
+function giveBackAnimal () public{
+    animalType  _currentpet = borrowed[msg.sender];
+    require (_currentpet != animalType.None, "No borrowed pets");
+    numberOfAnimals [_currentpet] += 1;
+    emit Returned(_currentpet);
+    borrowed[msg.sender] = animalType.None;
+}
+
+}