n_q=int(input())
undo_stack=[]
s=""

def perform(op, param, in_undo=False):
    global s
    match op:
        case 'append':
            if not in_undo:
                undo_stack.append(('delete', len(param)))
            s+= param
        case 'delete':
            if not in_undo:
                 undo_stack.append(('append', s[len(s)-int(param):])) 
            s = s[0:len(s)-int(param)]
        case 'print':
            print(s[int(param)-1])
        case 'undo':
            un_op, un_param = undo_stack.pop()
            perform(un_op, un_param, in_undo=True)

            
ops=['ops','append','delete','print','undo']  
for _ in range(n_q):
    q=input().split()
    op=ops[int(q[0])]
    param = None
    if op!='undo':
        param=q[1]
    #now, perform
    perform(op, param)