#include <iostream>
#include <vector>
#include<bits/stdc++.h>
using namespace std;
 
int main() {
 
    vector<char> arr = {'x', 'y', 'x', 'x', 'y', 'x', 'y', 'y'};
    int n = arr.size();
	int x_count = 0 ; int y_count = 0 ;
	int count = 0 ;  
	unordered_map<int,int>hash;
	hash[0]=1;
	for(int i = 0 ; i<n;i++){
		if(arr[i]=='x') x_count++;
	           else {
		y_count++;
	             }
	int diff = x_count-y_count;
	count+=hash[diff];
	hash[diff] ++;
	}
	cout<<count;
 
 
    return 0;
}
 

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