Reversing Stack

Reverse All the Elements of a Stack within That Stack... w/ only Stack Operations.

#include <iostream>
#include <stack>

using namespace std;

int main() {
    stack <int> S;
    stack <int> temp;
    stack <int> temp2;

    cout << "Enter the Stack Elements (-1 to stop): ";

    int n;
    while(true) {
        cin >> n;
        if(n < 0) break;

        S.push(n);
    }

    while(!S.empty()) {
        temp.push(S.top());
        S.pop();
    }

    while(!temp.empty()) {
        temp2.push(temp.top());
        temp.pop();
    }

    while(!temp2.empty()) {
        S.push(temp2.top());
        temp2.pop();
    }

    return 0;
}