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#F1422. Running Track

    ID: 1428 传统题 2000ms 256MiB 尝试: 0 已通过: 0 难度: 6 上传者: 标签>动态规划贪心字符串算法思想数据结构提高难度共享题库Codeforces英文题面题目来源题面语言

Running Track

题目描述

C. Running Track
time limit per test
1 second
memory limit per test
512 megabytes
input
standard input
output
standard output

A boy named Ayrat lives on planet AMI-1511. Each inhabitant of this planet has a talent. Specifically, Ayrat loves running, moreover, just running is not enough for him. He is dreaming of making running a real art.

First, he wants to construct the running track with coating t. On planet AMI-1511 the coating of the track is the sequence of colored blocks, where each block is denoted as the small English letter. Therefore, every coating can be treated as a string.

Unfortunately, blocks aren't freely sold to non-business customers, but Ayrat found an infinite number of coatings s. Also, he has scissors and glue. Ayrat is going to buy some coatings s, then cut out from each of them exactly one continuous piece (substring) and glue it to the end of his track coating. Moreover, he may choose to flip this block before glueing it. Ayrat want's to know the minimum number of coating s he needs to buy in order to get the coating t for his running track. Of course, he also want's to know some way to achieve the answer.

Input

First line of the input contains the string s− the coating that is present in the shop. Second line contains the string t− the coating Ayrat wants to obtain. Both strings are non-empty, consist of only small English letters and their length doesn't exceed 2100.

Output

The first line should contain the minimum needed number of coatings n or -1 if it's impossible to create the desired coating.

If the answer is not -1, then the following n lines should contain two integers xi and yi− numbers of ending blocks in the corresponding piece. If xiyi then this piece is used in the regular order, and if xi>yi piece is used in the reversed order. Print the pieces in the order they should be glued to get the string t.

Examples
Input
abc
cbaabc
Output
2
3 1
1 3
Input
aaabrytaaa
ayrat
Output
3
1 1
6 5
8 7
Input
ami
no
Output
-1
Note

In the first sample string "cbaabc" = "cba" + "abc".

In the second sample: "ayrat" = "a" + "yr" + "at".


题目来源:fps-www.educg.net-codeforce-1-2833.xml.zip;FPS 共享题包,题包内第 927 题。保留原作者与原赛事署名。