#include <cstdio>
#include <utility>
#include <vector>
#include <complex>
#include <cmath>

using namespace std;

static const double EPS=1e-12;
static const double INF=1e24;

using Point=complex<double>;
using Plane=vector<Point>;
using Polygon=vector<Point>;

bool operator<(const Point &a, const Point &b) {
    return real(a)!=real(b)? real(a)<real(b) : imag(a)<imag(b);
}

double cross_prod(const Point &a, const Point &b) {
    return imag(conj(a)*b);
}

double dot_prod(const Point &a, const Point &b) {
    return real(conj(a)*b);
}

enum {
    ONLINE_FRONT=-2,
    CLOCKWISE,
    ON_SEGMENT,
    COUNTER_CLOCKWISE,
    ONLINE_BACK,
};

int ccwise(Point a, Point b, Point c) {
    b -= a; c -= a;

    if (cross_prod(b, c) > 0) {
        return COUNTER_CLOCKWISE;
    } else if (cross_prod(b, c) < 0) {
        return CLOCKWISE;
    } else if (dot_prod(b, c) < 0) {
        return ONLINE_BACK;
    } else if (norm(b) < norm(c)) {
        return ONLINE_FRONT;
    } else {
        return ON_SEGMENT;
    }
}

bool is_convex(Polygon g) {
    size_t V=g.size();
    for (size_t i=0; i<V; ++i) {
        int state=ccwise(g[i], g[(i+1)%V], g[(i+2)%V]);
        if (state == CLOCKWISE)
            return false;
    }

    return true;
}

int main() {
    size_t n;
    scanf("%zu", &n);

    Polygon g(n);
    for (size_t i=0; i<n; ++i) {
        double x, y;
        scanf("%lf %lf", &x, &y);
        g[i] = Point(x, y);
    }

    printf("%d\n", is_convex(g));
    return 0;
}