doctor's office

class Node {

    constructor(val) {
        this.next = null;
        this.prev = null;
        this.val = val;
    }
}

class doctorsOffice {

    constructor() {
        this.head = null;
        this.tail = null;
        this.count = 0;
        this.occurMap = new Map()
    }

    Append(name) {
        if (this.head === null) {
            this.head = new Node(name);
            this.tail = this.head;
            this.count++
            this.occurMap.set(name, this.occurMap.has(name) ? this.occurMap.get(name) + 1 : 1);
        } else {
            const newNode = new Node(name);
            newNode.prev = this.tail;
            this.tail.next = newNode;
            this.tail = this.tail.next;
            this.count++
            this.occurMap.set(name, this.occurMap.has(name) ? this.occurMap.get(name) + 1 : 1);
        }
        return 'OK';
    }

    Insert(position, name) {
        if (+position > this.count) return 'Error';

        if (position == 0 && this.head) {
            const newNode = new Node(name);
            this.head.prev = newNode;
            newNode.next = this.head;
            this.head = this.head.prev;
            this.count++
            this.occurMap.set(name, this.occurMap.has(name) ? this.occurMap.get(name) + 1 : 1);
            return 'OK';
        } else if (position == 0) {
            const newNode = new Node(name);
            this.head = newNode;
            this.tail = newNode;
            this.count++
            this.occurMap.set(name, this.occurMap.has(name) ? this.occurMap.get(name) + 1 : 1);
            return 'OK'
        } else if (position == this.count) {
            const newNode = new Node(name);
            newNode.prev = this.tail;
            this.tail.next = newNode;
            this.tail = this.tail.next;
            this.count++
            this.occurMap.set(name, this.occurMap.has(name) ? this.occurMap.get(name) + 1 : 1);
            return 'OK';
        } else {
            let temp = this.head;
            for (let i = 0; i < position - 1; i++) {
                temp = temp.next;
            }

            const newNode = new Node(name);
            newNode.prev = temp;
            newNode.next = temp.next;
            temp.next.prev = newNode;
            temp.next = newNode;
            this.occurMap.set(name, this.occurMap.has(name) ? this.occurMap.get(name) + 1 : 1);
            this.count++
            return 'OK'
        }
    }

    Find(name) {
        return this.occurMap.get(name) || 0
    }

    Examine(count) {
        if (this.count < count) return 'Error';
        let str = ''
        while (count) {
            if (this.head != this.tail) {
                this.occurMap.set(this.head.val, this.occurMap.get(this.head.val) - 1)
                str += this.head.val + ' ';
                this.head = this.head.next;

                count--
            } else {
                this.occurMap.set(this.head.val, this.occurMap.get(this.head.val) - 1)
                str += this.head.val + ' ';
                this.head = null;
                this.tail = null;
                count--
            }

            this.count--
        }


        return str.trim();
    }
}

const test = new doctorsOffice();

while (true) {
    const data = gets().split(' ')
    const command = data[0];
    const par1 = data[1];
    const par2 = data[2];

    if (command === 'End') break;

    print(test[command](par1, par2))
}