404459: GYM101510 E English

Vera has N rectangles. The i-th rectangle has corners (a_i, b_i) and (c_i, d_i). Let U be the union of the N rectangles. The intersection of U and the line y = s - x is composed of disjoint line segments (maybe degenerate ones). Let f(s) be the sum of the lengths of these line segments or be zero if the intersection is empty.

Given integers L and R, let . It can be seen that for some integer V. Compute the value of V.

Line 1 contains integers N, L, R (1 ≤ N ≤ 10³,  - 2 × 10⁸ ≤ L < R ≤ 2 × 10⁸).

N lines follow. The i-th line contains integers a_i, b_i, c_i, d_i ( - 10⁸ ≤ a_i < c_i ≤ 10⁸,  - 10⁸ ≤ b_i < d_i ≤ 10⁸).

Print one line with one integer, the value of V.

3 -1 3
-2 -1 0 2
-1 0 1 1
1 -2 2 -1

7

The below figure illustrates the first example when s = 0. f(0) is the sum of the lengths of the two thick blue line segments. Note that .