struct pt {
    int x, y;
    double value;

    inline double val() const {
        return atan2(y, x);
    }
    inline bool operator < (const pt &p) const {
        return value < p.value;
    }
};

const int maxn = (int)1e6;
pt ps[maxn];

int main() {
    #ifdef DEBUG
        freopen(TASKNAME".in", "r", stdin);
        freopen(TASKNAME".out", "w", stdout);
    #endif

    int n;
    while (scanf("%d", &n) >= 1) {
        for (int i = 0; i < n; i++) {
            scanf("%d%d", &ps[i].x, &ps[i].y);
            if (!ps[i].x && !ps[i].y) {
                while (1) ;
            }
            ps[i].value = ps[i].val();
        }

        for (int i = 0; i < n; i++)
            assert(ps[i].value == ps[i].val());