#include #include using namespace std; int main() { int Px, Py, Qx, Qy; double x_diff, y_diff; cin >> Px >> Py >> Qx >> Qy; x_diff = (Px - Qx > 0) ? Px - Qx : Qx - Px; y_diff = (Py - Qy > 0) ? Py - Qy : Qy - Py; cout << (x_diff + y_diff) / 2 << endl; return 0; }