#P1203D2. Remove the Substring (hard version)

    ID: 1770 远端评测题 2000ms 256MiB 尝试: 0 已通过: 0 难度: 5 上传者: 标签>binary searchgreedyimplementationtwo pointers*1700

Remove the Substring (hard version)

Description

The only difference between easy and hard versions is the length of the string.

You are given a string $s$ and a string $t$, both consisting only of lowercase Latin letters. It is guaranteed that $t$ can be obtained from $s$ by removing some (possibly, zero) number of characters (not necessary contiguous) from $s$ without changing order of remaining characters (in other words, it is guaranteed that $t$ is a subsequence of $s$).

For example, the strings "test", "tst", "tt", "et" and "" are subsequences of the string "test". But the strings "tset", "se", "contest" are not subsequences of the string "test".

You want to remove some substring (contiguous subsequence) from $s$ of maximum possible length such that after removing this substring $t$ will remain a subsequence of $s$.

If you want to remove the substring $s[l;r]$ then the string $s$ will be transformed to $s_1 s_2 \dots s_{l-1} s_{r+1} s_{r+2} \dots s_{|s|-1} s_{|s|}$ (where $|s|$ is the length of $s$).

Your task is to find the maximum possible length of the substring you can remove so that $t$ is still a subsequence of $s$.

The first line of the input contains one string $s$ consisting of at least $1$ and at most $2 \cdot 10^5$ lowercase Latin letters.

The second line of the input contains one string $t$ consisting of at least $1$ and at most $2 \cdot 10^5$ lowercase Latin letters.

It is guaranteed that $t$ is a subsequence of $s$.

Print one integer — the maximum possible length of the substring you can remove so that $t$ is still a subsequence of $s$.

Input

The first line of the input contains one string $s$ consisting of at least $1$ and at most $2 \cdot 10^5$ lowercase Latin letters.

The second line of the input contains one string $t$ consisting of at least $1$ and at most $2 \cdot 10^5$ lowercase Latin letters.

It is guaranteed that $t$ is a subsequence of $s$.

Output

Print one integer — the maximum possible length of the substring you can remove so that $t$ is still a subsequence of $s$.

Samples

bbaba
bb
3
baaba
ab
2
abcde
abcde
0
asdfasdf
fasd
3