CF314B Sereja and Periods

Let's introduce the designation , where $ x $ is a string, $ n $ is a positive integer and operation " $ + $ " is the string concatenation operation. For example, $ [abc,2]=abcabc $ . We'll say that string $ s $ can be obtained from string $ t $ , if we can remove some characters from string $ t $ and obtain string $ s $ . For example, strings $ ab $ and $ aсba $ can be obtained from string $ xacbac $ , and strings $ bx $ and $ aaa $ cannot be obtained from it. Sereja has two strings, $ w=[a,b] $ and $ q=[c,d] $ . He wants to find such maximum integer $ p $ $ (p>0) $ , that $ [q,p] $ can be obtained from string $ w $ .

The first line contains two integers $ b $ , $ d $ $ (1

In a single line print an integer — the largest number $ p $ . If the required value of $ p $ doesn't exist, print 0.