#include <iostream>

using namespace std;
const int max_size = 1000;
struct magacin {
    string a[max_size];
    int at;

    void init() {
        at = -1;
    }

    bool isFull() {
        if(at == max_size - 1) {
            return true;
        }
        return false;
    }
    bool isEmpty() {
        if(at == -1) {
            return true;
        }
        return false;
    }
    void push(string s) {
        if(isFull()) {
            cout << "Full stack size!" << endl;
            return;
        }
        at++;
        a[at] = s;
    }
    string pop() {
        if(isEmpty()) {
            cout << "Stack is empty!" << endl;
            exit(0);
        }
        string s = a[at];
        at--;
        return s;
    }
    string top() {
        if(isEmpty()) {
            cout << "Stack is empty!" << endl;
            exit(0);
        }
        return a[at];
    }
    int size() {
        return at + 1;
    }


};

struct red {
    string a[max_size];
    int front, rear;

    void init() {
        front = 0;
        rear = -1;
    }

    bool isEmpty() {
        if(rear == -1) {
            return true;
        }
        return false;
    }

    bool isFull() {
        if(rear == max_size - 1) {
            return true;
        }
        return false;
    }
    void push(string s) {
        if(isFull()) {
            cout << "Queue is full" << endl;
            exit(0); // terminate/exit the program
        }
        rear++;
        a[rear] = s;
    }

    string pop() {
        if(isEmpty()) {
            cout << "Queue is empty!" << endl;
            exit(0);
        }
        string s = a[front];
        for(int i = front; i < rear; i++) {
            a[i] = a[i + 1];
        }
        rear--;
        return s;
    }

    string peek() {
        if(isEmpty()) {
            cout << "Queue is empty! " << endl;
            exit(0);
        }
        return a[front];
    }
    int size() {
        return rear + 1;
    }

};

int get_number_of_unpaired_shoes(red Q) {
    magacin st;
    st.init();

    int paired_shoes = 0;
    while(!Q.isEmpty()) {
        string shoe = Q.peek();
        Q.pop();

        if(st.size() > 0 && st.top() != shoe) {
            st.pop();
            paired_shoes++;
        }
        else {
            st.push(shoe);
        }
    }

    cout << "Number of paired shoes: " << paired_shoes << endl;

    cout << "Number of unpaired shoes: " << st.size() << endl;


    return st.size();
}

int main()
{
    int n;
    cout << "Input number of shoes: ";
    cin >> n;

    red Q;
    Q.init();
    for(int i = 0; i < n; i++) {
        string shoe;
        cin >> shoe;
        Q.push(shoe);
    }
    get_number_of_unpaired_shoes(Q);


    return 0;

}