import java.util.Stack import java.util.StringTokenizer fun main() { val br = System.`in`.bufferedReader() val left = Stack() val right = Stack() val str = br.readLine() for (c in str) { left.push(c) } val m = br.readLine().toInt() repeat(m) { val token = StringTokenizer(br.readLine()) when (token.nextToken().first()) { 'L' -> { if (left.isNotEmpty()) { right.push(left.pop()) } } 'D' -> { if (right.isNotEmpty()) { left.push(right.pop()) } } 'B' -> { if (left.isNotEmpty()) { left.pop() } } 'P' -> { left.push(token.nextToken().first()) } } } val sb = StringBuilder() for (c in left) { sb.append(c) } for (c in right) { sb.append(c) } println(sb) }