Find correct assignment statements. Part $1$

Cost: $10|$ Solved: $10$

Memory limit: $256$ Mb

Time limit: $1000$ ms

Input file: stdin

Output file: stdout

Task:

You are given a set of strings separated with line feed characters.

Find all the substrings that are correct assignment statements.

In this task a string is considered to be a correct assignment statement when:

a variable is assigned to a constant value;

a variable is assigned to another variable.

For example, the strings $"$a$9$f $=7$;$"$ and $"a=b$;;$"$ are considered to be correct assignment statements $($note that there is a semicolon at the end of each statement$).$

The strings $"a=6","a-=10$; $","$d$=$#$&$\_$h$"$ are considered to be incorrect.

Input:

A set of strings separated with line feed characters.

Output:

All the longest correct substrings in the order in which they appear in the text, separating each with a line feed character.

$**$ Use only C$++**$