Given two strings `s`

and `t`

, find the number of ways you can choose a non-empty substring of `s`

and replace a **single character** by a different character such that the resulting substring is a substring of `t`

. In other words, find the number of substrings in `s`

that differ from some substring in `t`

by **exactly** one character.

For example, the underlined substrings in `"`

and __compute__r"`"`

only differ by the __computa__tion"`'e'`

/`'a'`

, so this is a valid way.

Return *the number of substrings that satisfy the condition above.*

A **substring** is a contiguous sequence of characters within a string.

**Example 1:**

Input:s = "aba", t = "baba"Output:6Explanation:The following are the pairs of substrings from s and t that differ by exactly 1 character: ("aba", "baba") ("aba", "baba") ("aba", "baba") ("aba", "baba") ("aba", "baba") ("aba", "baba") The underlined portions are the substrings that are chosen from s and t.

Input:s = "ab", t = "bb"Output:3Explanation:The following are the pairs of substrings from s and t that differ by 1 character: ("ab", "bb") ("ab", "bb") ("ab", "bb") The underlined portions are the substrings that are chosen from s and t.

Input:s = "a", t = "a"Output:0

**Example 4:**

Input:s = "abe", t = "bbc"Output:10

**Constraints:**

`1 <= s.length, t.length <= 100`

`s`

and`t`

consist of lowercase English letters only.

class Solution {
public int countSubstrings(String s, String t) {
}
}