void input() {
for (int i = 0; i < n; i++) {
double x, y;
scanf("%lf%lf", &x, &y);
c1.push_back(Point(x, y));
}
for (int i = 0; i < m; i++) {
double x, y;
scanf("%lf%lf", &x, &y);
c2.push_back(Point(x, y));
}
}
double area(Convex a) {
double sum = 0;
a.push_back(a[0]);
for (int i = 0; i < a.size() - 1; i++) {
sum += cross(a[i], a[i+1]);
}
return sum / 2.0;
}