Remove Adjacent Duplicates

Given a string s consisting of lowercase alphabets, remove all adjacent duplicate characters repeatedly until no more removals can be performed.

This process is defined as follows: if two consecutive characters s[i] and s[i+1] are the same, they are both removed. Formally, while there exists an index \(i\) such that \(s[i] = s[i+1]\), remove both characters from the string. The operation is applied repeatedly until the string cannot be reduced further.

For example:

• If the input is abbaca, the output is ca.
• If the input is azxxzy, the output is ay.

inputFormat

A single line containing the string s composed of lowercase alphabets.

outputFormat

A single line containing the resultant string after all adjacent duplicates have been removed.## sample

abbaca

ca