For this Question: Given a string S you have to remove all pairs of identical letters, which are consecutive. If after the removal there appear new pairs, remove them as well. Repeat this untill no adjacent letter in the string is same.
Note that deleting of the consecutive identical letters can be done in any order, as any order leads to the same result.The input data consists of a single string S.

Constraints:
1 <= |S| <= 100000
S contains lowercase english letters only.Print the given string after it is processed. It is guaranteed that the result will contain at least one character.Sample Input
hhoowaaaareyyoouu

Sample Output
wre

Explanation:
First we remove "hh" then "oo" then "aa" then "yy" then "oo" then "uu" and we are left with "wre".
Now we cannot remove anything.

Sample Input:-
abcde

Sample Output:-
abcde

Sample Input:-
abcddcb

Sample Output:-
a, I have written this Solution Code: #pragma GCC optimize ("Ofast")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define VV vector
#define pb push_back
#define bitc  __builtin_popcountll
#define m_p make_pair
#define infi 1e18+1
#define eps 0.000000000001
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL);
string char_to_str(char c){string tem(1,c);return tem;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class T>//usage rand<long long>()
T rand() {
    return uniform_int_distribution<T>()(rng);
}
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<class T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
// string to integer stoi()
// string to long long stoll()
// string.substr(position,length);
// integer to string to_string();
 
//////////////
auto clk=clock();
#define all(x) x.begin(),x.end()
#define S second
#define F first
#define sz(x) ((long long)x.size())
#define int long long  
#define f80 __float128
#define pii pair<int,int>
/////////////

signed main(){
	fastio;
	#ifdef ANIKET_GOYAL
		freopen("inputf.in","r",stdin);
		freopen("outputf.in","w",stdout);
	#endif
    string s;
    cin>>s;
	int len=s.length();
    char stk[410000];
    int k = 0;
    for (int i = 0; i < len; i++)
    {
        stk[k++] = s[i];
        while (k > 1 && stk[k - 1] == stk[k - 2])
            k -= 2;
    }
    for (int i = 0; i < k; i++)
        cout << stk[i];
 	return 0;
}, In this Programming Language: C++, Now tell me if this Code is compilable or not?