try(Scanner scan = new Scanner(System.in)){

	int n = scan.nextInt();
	scan.nextLine();

	Stack<String> history = new Stack<>();
	String text="" ;

	for (int i = 0; i < n; i++) {
		int command = scan.nextInt();
		switch(command){
			case 1:
			history.push(text);
			text+=scan.nextLine().trim();
			break;
			case 2:
			history.push(text);
			text = text.substring(0, text.length()-scan.nextInt());
			break;
			case 3:
			System.out.println(text.charAt(scan.nextInt()-1));
			break;
			case 4:
			text= history.pop(); 
			break;                    
		}
	}
}        

Q = int(input())
S = str()
prev = []

operations = []
for i in range(Q):
    operations.append(input().split(" "))
    
for i, op in enumerate(operations):
    match op[0]:
        case "1":
            prev.append(S)
            S += op[1]
        case "2":
            prev.append(S)
            S = S[:-int(op[1])]
        case "3":
            print(S[int(op[1])-1])
        case "4":
            S = prev[-1]
            prev.pop()

public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(System.out));

        int Q = Integer.parseInt(bufferedReader.readLine().trim());
        StringBuilder S = new StringBuilder();
        Stack<String> history = new Stack<>();

        for (int i = 0; i < Q; i++) {
            String[] inputs = bufferedReader.readLine().split(" ");
            int type = Integer.parseInt(inputs[0]);

            switch (type) {
                case 1: // Append(W)
                    history.push(S.toString());
                    S.append(inputs[1]);
                    break;
                case 2: // Delete(k)
                    int k = Integer.parseInt(inputs[1]);
                    history.push(S.toString());
                    S.delete(S.length() - k, S.length());
                    break;
                case 3: // Print(k)
                    int index = Integer.parseInt(inputs[1]) - 1;
                    bufferedWriter.write(S.charAt(index));
                    bufferedWriter.newLine();
                    break;
                case 4: // Undo
                    S = new StringBuilder(history.pop());
                    break;
            }
        }

        bufferedReader.close();
        bufferedWriter.flush();
        bufferedWriter.close();
    }

function processData(input) {
    const undo = [""];
    const operations = [
        (append) => undo.push(undo.at(-1) + append),
        (_delete) => undo.push(undo.at(-1).slice(0, undo.at(-1).length - _delete)),
        (print) => console.log(undo.at(-1).at(print - 1)),
        () => undo.pop()
    ];
    input.split("\n").slice(1).forEach((operation) => operations[operation.split(" ")[0] - 1](operation.split(" ")[1]));
}

public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner input = new Scanner(System.in);
        int q = input.nextInt();
        
        Stack<String> stack = new Stack<>();
        StringBuilder sb = new StringBuilder();
        
        for(int j = 0; j < q; j++) {
            int choose = input.nextInt();
            switch(choose) {
                case 1:
                    stack.push(sb.toString());
                    String newText = input.next();
                    sb.append(newText);
                    break;
                case 2:
                    stack.push(sb.toString());
                    int k = input.nextInt();
                    sb.delete(sb.length() - k, sb.length());
                    break;
                case 3:
                    int kth = input.nextInt();
                    System.out.println(sb.charAt(kth - 1));
                    break;
                case 4:
                    sb.setLength(0);
                    sb.append(stack.pop());
                    break;
            }
        }
    }