Dorm Friendship Largest Circle

A residence hall has n students, numbered 1 through n. There are m recorded friendships; each friendship links two students, and friendship is mutual. Students a and b belong to the same friendship circle if a can reach b through a chain of friendships.

Report the size (number of students) of the largest friendship circle.

Input format

• Line 1: two integers n and m.
• Next m lines: two integers u and v (1-indexed), a friendship between student u and student v. The same pair may be listed more than once.

Output format

A single integer: the number of students in the largest friendship circle.

Constraints

• 1 <= n <= 100000
• 0 <= m <= 200000
• 1 <= u, v <= n