3 1
erase -1
erase 0
erase -2147483648
 26 25
defragment
erase 1
erase -1560200883
alloc 44
defragment
alloc 75
alloc 22
defragment
erase 4
defragment
alloc 57
alloc 53
erase 4
erase -1639632026
erase -2121605039
erase 3
alloc 51
alloc 65
defragment
erase 2
erase 4
alloc 52
erase 3
defragment
erase -1842529282
erase 3
 12 40
erase 1
alloc 21
alloc 5
alloc 7
defragment
defragment
erase 2
alloc 83
erase 4
defragment
alloc 59
defragment
 44 46
alloc 28
alloc 36
defragment
erase -937404236
alloc 71
defragment
alloc 81
alloc 51
erase 3
defragment
alloc 48
erase 1
defragment
alloc 36
defragment
defragment
erase 1
defragment
defragment
erase -1173350787
alloc 94
erase 5
defragment
erase 9
alloc 98
erase 7
defragment
erase 5
erase 1
defragment
erase 2
defragment
erase 4
defragment
erase 9
alloc 8
defragment
erase 9
defragment
defragment
defragment
erase 1
alloc 70
erase 9
 7 6
alloc 1
alloc 2
alloc 3
erase 1
defragment
erase 3
alloc 4
 47 43
erase 1
alloc 95
alloc 53
erase 2
defragment
alloc 100
erase 4
erase 2
erase -849472053
defragment
erase -638355221
alloc 90
erase 3
erase 2
defragment
alloc 17
erase 5
defragment
erase 6
defragment
erase 3
defragment
defragment
alloc 99
alloc 69
alloc 80
erase 9
erase 5
defragment
erase 7
defragment
alloc 93
defragment
defragment
alloc 25
defragment
alloc 14
erase 8
erase 4
defragment
defragment
alloc 96
erase 9
alloc 63
erase 8
defragment
erase 10
 8 50
alloc 51
defragment
alloc 100
defragment
erase 1
alloc 50
defragment
alloc 50
 6 1
defragment
alloc 10
alloc 1
erase -1
erase 1
erase 1
 26 25
alloc 25
erase 1
alloc 24
erase 2
alloc 23
erase 3
alloc 24
erase 4
alloc 24
erase 5
alloc 21
erase 6
alloc 24
erase 7
alloc 25
erase 8
alloc 25
erase 9
alloc 24
erase 10
alloc 25
erase 11
alloc 25
erase 12
alloc 25
erase 13
 10 10
alloc 10
erase -1
erase 1
alloc 5
erase -1
alloc 5
erase 0
alloc 5
erase 0
alloc 5
 37 74
alloc 11
defragment
erase 1
defragment
erase 2
defragment
alloc 90
erase 3
erase 2
erase 3
erase 1
erase 1
alloc 38
alloc 19
erase 1
erase 3
defragment
alloc 93
erase 5
erase 4
alloc 66
alloc 71
erase 5
defragment
defragment
defragment
defragment
erase 7
alloc 47
erase -95616683
erase 2
alloc 28
alloc 32
erase 11
alloc 50
defragment
defragment
 19 46
alloc 21
erase 2
erase 1
defragment
alloc 4
defragment
defragment
alloc 40
erase 1
defragment
defragment
alloc 68
erase -388966015
alloc 85
alloc 53
erase 4
defragment
alloc 49
alloc 88
 12 10
alloc 6
alloc 2
erase 1
alloc 4
alloc 2
erase 3
alloc 2
alloc 3
alloc 1
alloc 1
alloc 1
alloc 1
 16 10
alloc 10
defragment
defragment
defragment
alloc 10
erase 1
erase 2
alloc 6
defragment
defragment
alloc 4
defragment
defragment
erase 2
defragment
alloc 6
 14 100
alloc 99
alloc 1
alloc 1
erase 2
alloc 1
erase 4
erase 1
alloc 100
alloc 1
alloc 99
defragment
erase 4
alloc 100
alloc 99
 22 9
alloc 9
erase 1
alloc 9
erase 2
alloc 9
erase 3
alloc 9
erase 4
alloc 9
erase 5
alloc 9
erase 6
alloc 9
erase 7
alloc 9
erase 8
alloc 9
erase 9
alloc 9
erase 10
alloc 9
erase 11
 42 98
defragment
defragment
defragment
defragment
defragment
alloc 5
alloc 66
defragment
erase 3
alloc 53
defragment
erase 4
erase 2
alloc 70
erase 3
defragment
defragment
erase 2
erase 3
erase -1327931832
alloc 93
alloc 64
erase 7
erase 6
erase 3
alloc 61
alloc 12
alloc 65
erase 2
alloc 46
erase 11
erase 9
erase 9
erase 6
alloc 2
alloc 78
defragment
erase 13
erase 6
erase 10
alloc 53
alloc 46
 16 10
alloc 10
defragment
defragment
defragment
alloc 10
erase 1
erase 2
alloc 6
defragment
defragment
alloc 4
defragment
defragment
erase 3
defragment
alloc 6
 38 18
alloc 72
erase 2
alloc 50
defragment
erase 3
defragment
alloc 43
alloc 41
defragment
defragment
alloc 26
alloc 46
alloc 16
alloc 15
defragment
defragment
alloc 95
erase 7
erase 7
erase 5
erase 2
erase 9
erase 7
alloc 43
defragment
erase 7
defragment
alloc 48
alloc 77
erase 10
erase 11
alloc 16
alloc 84
erase 1
defragment
alloc 86
defragment
erase 13
 16 49
erase -751005193
defragment
alloc 37
alloc 82
erase 3
erase 1
alloc 80
alloc 51
defragment
alloc 74
erase 1
alloc 91
defragment
defragment
alloc 98
defragment
 22 9
erase 1
alloc 6
alloc 65
erase 1
alloc 87
erase -1638927047
alloc 5
erase 2
alloc 70
defragment
alloc 20
alloc 48
erase -69401977
alloc 20
defragment
erase 7
defragment
erase 9
erase 7
erase 4
defragment
alloc 66
 7 100
alloc 100
erase 2147483647
erase 1
alloc 50
alloc 50
erase 3
erase -2147483648

ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
 ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
1
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
 ILLEGAL_ERASE_ARGUMENT
1
2
3
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
 1
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
2
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
3
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
 1
2
3
4
 ILLEGAL_ERASE_ARGUMENT
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
1
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
2
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
 NULL
NULL
ILLEGAL_ERASE_ARGUMENT
1
NULL
 NULL
1
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
 1
2
3
4
5
6
7
8
9
10
11
12
13
 1
ILLEGAL_ERASE_ARGUMENT
2
ILLEGAL_ERASE_ARGUMENT
3
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
 1
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
2
3
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
4
5
ILLEGAL_ERASE_ARGUMENT
NULL
 1
ILLEGAL_ERASE_ARGUMENT
2
3
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
 1
2
3
4
5
NULL
6
7
8
9
 1
NULL
ILLEGAL_ERASE_ARGUMENT
2
3
4
 1
2
NULL
3
ILLEGAL_ERASE_ARGUMENT
NULL
4
NULL
NULL
NULL
 1
2
3
4
5
6
7
8
9
10
11
 1
2
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
3
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
4
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
 1
NULL
ILLEGAL_ERASE_ARGUMENT
2
3
NULL
 NULL
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
NULL
NULL
1
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
 ILLEGAL_ERASE_ARGUMENT
1
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
NULL
 ILLEGAL_ERASE_ARGUMENT
1
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
2
NULL
NULL
NULL
ILLEGAL_ERASE_ARGUMENT
NULL
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
ILLEGAL_ERASE_ARGUMENT
NULL
 1
ILLEGAL_ERASE_ARGUMENT
2
3
ILLEGAL_ERASE_ARGUMENT

//package com.company;

import javax.management.MBeanAttributeInfo;
import java.awt.geom.Line2D;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;


public class MemoryManager {

    public static void print(List<MemoryBlock> list) {
        for (MemoryBlock block : list) {
            System.out.print(block.allocated + " " + block.size+" ");
        }
        System.out.println();
    }
    public static void main(String[] args) {
        FastScanner scanner = new FastScanner();
        int t = scanner.nextInt();
        int m = scanner.nextInt();
        Memory memory = new Memory(m);
        String command = null;
        int argument = 0;
        for (int i = 0; i < t; i++) {
            command = scanner.next();
            if (command.equals("alloc")) {
                argument = scanner.nextInt();
                int identifier = memory.alloc(argument);
                if (identifier == 0) {
                    System.out.println("NULL");
                } else {
                    System.out.println(identifier);
                }
            } else if (command.equals("erase")) {
                argument = scanner.nextInt();
                if (!memory.erase(argument)) {
                    System.out.println("ILLEGAL_ERASE_ARGUMENT");
                }
            } else {
                memory.defragment();
            }

        }
    }

    public static class MemoryBlock{
        public boolean allocated;
        public int size;
    }

    public static class Memory {
        private Map<Integer, MemoryBlock> allocation;
        private List<MemoryBlock> memory;
        private int identifier = 0;

        public Memory(int capacity) {
            allocation = new HashMap<>();
            memory = new LinkedList<>();
            MemoryBlock block = new MemoryBlock();
            block.allocated =false;
            block.size = capacity;
            memory.add(block);
        }

        public int alloc(int size) {
            Iterator<MemoryBlock> iterator = memory.iterator();
            int index = 0;
            while (iterator.hasNext()) {
                MemoryBlock block = iterator.next();
                if (!block.allocated && block.size >= size) {
                    MemoryBlock remainder = new MemoryBlock();
                    remainder.size = block.size - size;
                    remainder.allocated = false;
                    block.size = size;
                    block.allocated = true;
                    memory.add(++index, remainder);
                    allocation.put(++identifier,block);
//                    print(memory);
                    return identifier;
                }
                index++;
            }
            return 0;
        }

        public boolean erase(int identifier) {
            if (allocation.get(identifier) == null) {
                return false;
            }
            MemoryBlock allocated = allocation.get(identifier);
            MemoryBlock previous = null;
            Iterator<MemoryBlock> iterator = memory.iterator();
            while (iterator.hasNext()) {
                MemoryBlock block = iterator.next();
                if (block == allocated) {
                    if (previous != null && !previous.allocated) {
                        block.size += previous.size;
                        memory.remove(previous);
                    }
                    if (iterator.hasNext()) {
                        MemoryBlock next = iterator.next();
                        if (!next.allocated) {
                            block.size += next.size;
                            memory.remove(next);
                        }
                    }
                    block.allocated = false;
                }
            }
//            print(memory);
            return true;
        }

        public void defragment() {
            Iterator<MemoryBlock> iterator = memory.iterator();
            int availableCapacity = 0;
            while (iterator.hasNext()) {
                MemoryBlock block = iterator.next();
                if (!block.allocated) {
                    availableCapacity += block.size;
                    iterator.remove();
                }
            }
            MemoryBlock remain = new MemoryBlock();
            remain.allocated = false;
            remain.size = availableCapacity;
            memory.add(remain);
        }
    }


    public static class FastScanner {
        private StringTokenizer st;
        private BufferedReader br;
        public FastScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        public int nextInt() {
            return Integer.parseInt(next());
        }
    }
}
