I am going to provide you with some code, the state of the environment, and the state of the concrete heap and abstract heap. The environment and heaps will be provided in JSON format. We just finished iteration number 1 of the loop on line 40. Please merge nodes in the heap to achieve the best balance of scalability and precision for detecting `TypeError: Cannot read properties of null or undefined`. 


Here is the code:
```javascript
var person1 = {
    "name": "John Doe",
    "occupation": "Software Engineer",
}
var person2 = {
    "name": "Jane Smith",
    "occupation": "Doctor",
}
var person3 = {
    "name": "Michael Wang",
    "occupation": "Phd Student",
}
var occupation1 = {"occupation": "Software Engineer",
                     "salary": 100000,
                     "location": "San Francisco",
};
var occupation2 = {"occupation": "Doctor",
                        "salary": 200000,
                        "location": "New York",
    };

var occupation3 = {"occupation": "Phd Student",
                        "salary": 30000,
                        "location": "Boston"
};
function get_occupation(index) {
    var all_occupations = ["Software Engineer", "Doctor", "Phd Student"];
    return all_occupations[index % 3];
}
function get_name(index) {
    var all_names = ["Kevin Wilson", "Olivia Martinez", "James Anderson"];
    return all_names[index % 3];
}
function get_salary(index) {
    var salaries = [180000, 25000, 40000];
    return salaries[index % 3];
}
function add_people_and_occupations(people, occupations) {
    var n = getN();
    for (var i = 3; i < n; i = i+1) {
        var name = get_name(i);
        var occupation_name = get_occupation(i);
        var salary = get_salary(i);
        var occupation = {"occupation": occupation_name, "salary": salary};
        var person = {"name": name, "occupation": occupation_name};
        people[i] = person;
        occupations[i] = occupation;
    }
    return [people, occupations];
}
var people = {0: person1, 1: person2, 2: person3};
var occupations = {0: occupation1, 1: occupation2, 2: occupation3};
var people_and_occupations = add_people_and_occupations(people, occupations);
```

Here is the current state of the environment:
```json
{
  "people": [
    "Abstract Address(4)"
  ],
  "occupations": [
    "Abstract Address(8)"
  ],
  "n": [
    "TOP"
  ],
  "i": [
    3
  ],
  "name": [
    "Kevin Wilson"
  ],
  "occupation_name": [
    "Software Engineer"
  ],
  "salary": [
    180000
  ],
  "occupation": [
    "Abstract Address(10)"
  ],
  "person": [
    "Abstract Address(9)"
  ]
}
```

Here is the current state of the concrete heap:
```json
{
  "Concrete Address(11)": {
    "0": [
      "Kevin Wilson"
    ],
    "1": [
      "Olivia Martinez"
    ],
    "2": [
      "James Anderson"
    ]
  },
  "Concrete Address(13)": {
    "0": [
      "Software Engineer"
    ],
    "1": [
      "Doctor"
    ],
    "2": [
      "Phd Student"
    ]
  },
  "Concrete Address(15)": {
    "0": [
      180000
    ],
    "1": [
      25000
    ],
    "2": [
      40000
    ]
  }
}
```

Here is the current state of the abstract heap:
```json
{
  "Abstract Address(1)": {
    "name": [
      "John Doe"
    ],
    "occupation": [
      "Software Engineer"
    ]
  },
  "Abstract Address(2)": {
    "name": [
      "Jane Smith"
    ],
    "occupation": [
      "Doctor"
    ]
  },
  "Abstract Address(3)": {
    "name": [
      "Michael Wang"
    ],
    "occupation": [
      "Phd Student"
    ]
  },
  "Abstract Address(4)": {
    "0": [
      "Abstract Address(1)"
    ],
    "1": [
      "Abstract Address(2)"
    ],
    "2": [
      "Abstract Address(3)"
    ],
    "3": [
      "Abstract Address(9)"
    ]
  },
  "Abstract Address(5)": {
    "occupation": [
      "Software Engineer"
    ],
    "salary": [
      100000
    ],
    "location": [
      "San Francisco"
    ]
  },
  "Abstract Address(6)": {
    "occupation": [
      "Doctor"
    ],
    "salary": [
      200000
    ],
    "location": [
      "New York"
    ]
  },
  "Abstract Address(7)": {
    "occupation": [
      "Phd Student"
    ],
    "salary": [
      30000
    ],
    "location": [
      "Boston"
    ]
  },
  "Abstract Address(8)": {
    "0": [
      "Abstract Address(5)"
    ],
    "1": [
      "Abstract Address(6)"
    ],
    "2": [
      "Abstract Address(7)"
    ],
    "3": [
      "Abstract Address(10)"
    ]
  },
  "Abstract Address(9)": {
    "name": [
      "Kevin Wilson"
    ],
    "occupation": [
      "Software Engineer"
    ]
  },
  "Abstract Address(10)": {
    "occupation": [
      "Software Engineer"
    ],
    "salary": [
      180000
    ]
  }
}
```

Please provide an abstraction by merging nodes in the concrete and abstract heap, and provide a mapping between which nodes have been merged in your output. Only specify the addresses you want to merge.
