Solution * 2

#include <iostream>
#include <cstdio>
using namespace std;
bool covered(int x, int y, int x1, int y1, int x2, int y2){
    return x >= x1 && x <= x2 && y >= y1 && y <= y2;
}
int main(){
    int x1, y1, x2, y2;
    cin >> x1 >> y1 >> x2 >> y2;
    int x3, y3, x4, y4;
    cin >> x3 >> y3 >> x4 >> y4;
    int corner_num = 0;
    if(covered(x1, y1, x3, y3, x4, y4)){
        corner_num++;
    }
    if(covered(x1, y2, x3, y3, x4, y4)){
        corner_num++;
    }
    if(covered(x2, y1, x3, y3, x4, y4)){
        corner_num++;
    }
    if(covered(x2, y2, x3, y3, x4, y4)){
        corner_num++;
    }
    if(corner_num < 2){
        cout << (x2 - x1) * (y2 - y1);
    }else if(corner_num == 4){
        cout << 0;
    }else{
        int xl = max(x1, x3);
        int xr = min(x2, x4);
        int yl = max(y1, y3);
        int yr = min(y2, y4);
        cout << (x2 - x1) * (y2 - y1) - (xr - xl) * (yr - yl);
    }
    return 0;
}