function processData(input) {
    let currentString = '';
    let operationHistory = [];
    const operations = input.split('\n').slice(1); 
    for (let op of operations) {
        const opArr = op.split(' ');
        const type = parseInt(opArr[0]);
        if (type === 1) { 
            const strToAppend = opArr[1];
            currentString += strToAppend;
            operationHistory.push({ type: 1, value: strToAppend }); 
        } else if (type === 2) { // Delete operation
            const numToDelete = parseInt(opArr[1]);
            const deletedString = currentString.slice(-numToDelete); 
            currentString = currentString.slice(0, -numToDelete); 
            operationHistory.push({ type: 2, value: deletedString }); 
        } else if (type === 3) { // Print operation
            const index = parseInt(opArr[1]) - 1; 
            console.log(currentString[index]);

        } else if (type === 4) { 
            const lastOperation = operationHistory.pop();
            if (lastOperation.type === 1) { // Undo append
                const appendedString = lastOperation.value;
                currentString = currentString.slice(0, -appendedString.length); 
            } else if (lastOperation.type === 2) { // Undo delete
                const deletedString = lastOperation.value;
                currentString += deletedString;
            }
        }
    }
}

class strEditor :
    def __init__(self):
        self.setting = []
        self.temp = []
    def createSetting(self):
        for s in [input() for _ in range(int(input()))]:
            main = s.split(" ")
            code = main[0]
            command = None
            if len(main) >1:
                command = main[1] 
            self.setting.append({"code":code,"command":command})
        return self.setting

    def operationMethod(self,code, command, finalS,idx):
        if int(code) == 1:
            self.temp.append(finalS)
            finalS+=(command)
        elif int(code) == 2:
            if 0 <= int(command) <= len(finalS):
                self.temp.append(finalS)
                finalS = finalS[:-int(command)] 
        elif int(code) == 3:
            if 1 <= int(command) <= len(finalS):
                print(finalS[int(command)-1])
        elif int(code) == 4:
            finalS = self.temp.pop()
        else:
            print("Invalid operation code.")
        return finalS
        
    def runCommand(self):
        finalS = ''
        for idx in range(len(self.setting)):
            payloads = self.setting[idx]
            code = payloads["code"]
            command = payloads["command"]
            finalS = self.operationMethod(code, command, finalS,idx)
        return finalS
        
editor = strEditor()
editor.createSetting()
editor.runCommand()

x = ['']
for s in [input() for _ in range(int(input()))]:
    x.append(x[-1]+s[2:]) if s[0] == '1' else x.append(x[-1][:-int(s[2:])]) if s[0] == '2' else print(x[-1][int(s[2:])-1]) if s[0] == '3' else x.pop() if s == '4' else ...