ACM详解(6)——栈收藏

堆栈是一种特殊的线性结构，后进先出，只能对栈顶元素操作，典型的操作入栈和出站。下面通过例子介绍基本用法。

题目：Train Problem

Problem Description

As the new term com es, the Ignatius Train Station is very busy nowadays. A l ot of student want to get back to school by train(because the trains in the Ignatiu s Train Station is the fastest all over the world ^v^). But here com es a problem, there is only one railway where all the trains stop. So all the trains com e in from one side and get out from the other side. For this problem, if train A gets into the railway first, and then train B gets into the railway before train A leaves, train A can't leave until train B leaves. The pictures below figure out the problem. Now th e problem for you is, there are at m ost 9 trains in the station, all the trains has a n ID(num bered from1 to n), the trains get into the railway in an order O1, your task is to determine whether the trains can get out in an order O2.

Input

The input contains several test cases. Each test case consists of an integer, th e num ber of trains, and two strings, the order of the trains com e in:O1, and the order of the trains leave:O2. The input is term inated by the end of file. More detai ls in the Sam ple Input.

Output

The output contains a string "No." if you can't ex change O2 to O1, or you sho uld output a line contains "Yes.", and then output your way in ex changing the ord er(you should output "in" for a train getting into the railway, and "out" for a train getting out of the railway). Print a line contains "FINISH" after each test case. M ore details in the Sam ple Output.

Sam ple Input

3 123 321

3 123 312