T5. Only two different

In a single line, you are given at least 3 integers, separated by spaces. If there are exactly two distinct numbers among them, output the number that appears more frequently. If both numbers appear with the same frequency, output the smaller one. If neither condition is met, output "NO".

The total number of integers will not exceed 30.

Each integer is within the range [-10^18, 10^18].

Input file format:

A single line containing the integers separated by spaces.

Output file format:

A single line containing the solution to the problem.

Examples