- #include <iostream> 
- #include <string> 
- using namespace std; 
-   
- int main() 
- { 
-     string a = "abbaca"; 
-     int i = 0; 
-     while (i < a.size()){ 
-         if (a[i] == a[i+1]){ 
-             a.erase(i, 2); 
-             i = 0; 
-         } 
-         else{ 
-             i++; 
-         } 
-     } 
-     cout << a; 
-   
-     return 0; 
- } 
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