#include <fstream>
#include <stack>
#define maxn 1000010
using namespace std;
ifstream fin ("status.in");
ofstream fout ("status.out");
char st[maxn];
string s;
int n,t;
int main ()
{
    fin>>n>>s;
    for (int i = 0; i < n; ++i)
    {
        if (t != 0 && st[t] == s[i])
            --t;
        else st[++t] = s[i];
    }
    for (int i = 1; i <= t; ++i)
        fout<<st[i];
}