int boardCutting(vector<int> cost_y, vector<int> cost_x) {
    long h = 1, v = 1;
    sort(cost_x.rbegin(), cost_x.rend());
    sort(cost_y.rbegin(), cost_y.rend());
    
    int s1 = 0, s2 = 0;
    long res = 0;
    while (s1 < cost_x.size() && s2 < cost_y.size()) {
        if (cost_x[s1] > cost_y[s2]) {
            res += cost_x[s1] * v;
            h++;
            s1++;
        } else {
            res += cost_y[s2] * h;
            v++;
            s2++;
        }
        res %= 1000000007;
        
    }
    
    while (s1 < cost_x.size()) {
        res += cost_x[s1] * v;
        res %= 1000000007;
        
        s1++;
    }
    
    while (s2 < cost_y.size()) {
        res += cost_y[s2] * h;
        res %= 1000000007;
        s2++;
    }
    
    return (int)(res % 1000000007);
}