import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.InputMismatchException;

public class Main {

    public static void main(String[] args) throws IOException{
	    InputReader in = new InputReader(new FileInputStream("trie.in"));
        //InputReader in = new InputReader(System.in);
        PrintWriter out = new PrintWriter("trie.out");
        //PrintWriter out = new PrintWriter(System.out);

        Trie T = new Trie();

        int op;
        while (in.hasNext()) {
            op = in.nextInt();
            String S = in.nextString();

            if (op == 0)
                T.insert(S);
            else if (op == 1)
                T.erase(S);
            else if (op == 2)
                out.println(T.count(S));
            else
                out.println(T.prefix(S));
        }

        out.close();
    }

    private static class Trie {
        private class Node {
            int cnt, nr;
            Node[] links;

            Node() {
                links = new Node[26];
                cnt = nr = 0;
            }
        }

        private Node root;

        Trie() {
            root = new Node();
        }

        public void insert(String S) {
            Node p = root;
            for (int i = 0; i < S.length(); ++i) {
                int x = S.charAt(i) - 'a';

                if (p.links[x] == null) {
                    p.links[x] = new Node();
                    p.nr++;
                }

                p = p.links[x];
            }

            p.cnt++;
        }

        public void erase(String S) {
            Node[] nodes = new Node[S.length() + 1];
            nodes[0] = root;
            for (int i = 0; i < S.length(); ++i) {
                int x = S.charAt(i) - 'a';

                nodes[i + 1] = nodes[i].links[x];
            }

            nodes[S.length()].cnt--;
            for (int i = S.length() - 1; i >= 0; --i) {
                int x = S.charAt(i) - 'a';

                if (nodes[i + 1].cnt == 0 && nodes[i + 1].nr == 0) {
                    nodes[i].links[x] = null;
                    nodes[i].nr--;
                }
            }
        }

        public int count(String S) {
            Node p = root;
            for (int i = 0; i < S.length(); ++i) {
                int x = S.charAt(i) - 'a';

                if (p.links[x] == null)
                    return 0;

                p = p.links[x];
            }

            return p.cnt;
        }

        public int prefix(String S) {
            Node p = root;

            for (int i = 0; i < S.length(); ++i) {
                int x = S.charAt(i) - 'a';

                if (p.links[x] == null)
                    return i;

                p = p.links[x];
            }

            return S.length();
        }
    }
}

class InputReader {
    private InputStream stream;
    private byte[] buf = new byte[4096];
    private int curChar;
    private int numChars;

    public InputReader(InputStream stream) {
        this.stream = stream;
    }

    public int read() {
        if (numChars == -1)
            throw new InputMismatchException();
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar++];
    }

    public int peek() {
        if (numChars == -1)
            return -1;
        if (curChar >= numChars) {
            curChar = 0;
            try {
                numChars = stream.read(buf);
            } catch (IOException e) {
                return -1;
            }
            if (numChars <= 0)
                return -1;
        }
        return buf[curChar];
    }

    public void skip(int x) {
        while (x-- > 0)
            read();
    }

    public int nextInt() {
        return Integer.parseInt(nextString());
    }

    public long nextLong() {
        return Long.parseLong(nextString());
    }

    public String nextString() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        StringBuffer res = new StringBuffer();
        do {
            res.appendCodePoint(c);
            c = read();
        } while (!isSpaceChar(c));

        return res.toString();
    }

    public String next() {
        return nextString();
    }

    public String nextLine() {
        StringBuffer buf = new StringBuffer();
        int c = read();
        while (c != '\n' && c != -1) {
            if (c != '\r')
                buf.appendCodePoint(c);
            c = read();
        }
        return buf.toString();
    }

    public double nextDouble() {
        int c = read();
        while (isSpaceChar(c))
            c = read();
        int sgn = 1;
        if (c == '-') {
            sgn = -1;
            c = read();
        }
        double res = 0;
        while (!isSpaceChar(c) && c != '.') {
            if (c == 'e' || c == 'E')
                return res * Math.pow(10, nextInt());
            if (c < '0' || c > '9')
                throw new InputMismatchException();
            res *= 10;
            res += c - '0';
            c = read();
        }
        if (c == '.') {
            c = read();
            double m = 1;
            while (!isSpaceChar(c)) {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                m /= 10;
                res += (c - '0') * m;
                c = read();
            }
        }
        return res * sgn;
    }

    public boolean hasNext() {
        int value;
        while (isSpaceChar(value = peek()) && value != -1)
            read();
        return value != -1;
    }

    private boolean isSpaceChar(int c) {
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

}