как мне добыть / вывести значение ключа и поместить его в document.write из массива в котором объект в котором в котором массив с объектом?

const gradation = {
    20: "satisfactory",
    55: "good",
    85: "very-good",
    100: "excellent"
};

const users = [
    {
        name: "Jack Smith",
        age: 23,
        img: "JackSmith",
        role: "student",
        courses: [
            {
                "title": "Front-end Pro",
                "mark": 20
            },
            {
                "title": "Java Enterprise",
                "mark": 100
            }
        ]
    },
    {
        name: "Amal Smith",
        age: 20,
        img: "AmalSmith",
        role: "student"
    },
    {
        name: "Noah Smith",
        age: 43,
        img: "NoahSmith",
        role: "student",
        courses: [
            {
                "title": "Front-end Pro",
                "mark": 50
            }
        ]
    },
    {
        name: "Charlie Smith",
        age: 18,
        img: "CharlieSmith",
        role: "student",
        courses: [
            {
                "title": "Front-end Pro",
                "mark": 75
            },
            {
                "title": "Java Enterprise",
                "mark": 23
            }]
    },
    {
        name: "Emily Smith",
        age: 30,
        img: "EmilySmith",
        role: "admin",
        courses: [
            {
                "title": "Front-end Pro",
                "score": 10,
                "lector": "Leo Smith"
            },
            {
                "title": "Java Enterprise",
                "score": 50,
                "lector": "David Smith"
            },
            {
                "title": "QA",
                "score": 75,
                "lector": "Emilie Smith"
            }]
    },
    {
        name: "Leo Smith",
        age: 253,
        img: "LeoSmith",
        role: "lector",
        courses: [
            {
                "title": "Front-end Pro",
                "score": 78,
                "studentsScore": 79
            },
            {
                "title": "Java Enterprise",
                "score": 85,
                "studentsScore": 85
            }
        ]
    }
];