B'"To curtain off the moonlight should be hardly possible; the shades present its mellow beauty and restful nature." Intonates Mino. "See? The clouds are coming." Kanno gazes into the distance. "That can 't be better," Mino turns to Kanno. The sky can be seen as a one-dimensional axis. The moon is at the origin whose coordinate is 0 . There are n clouds floating in the sky. Each cloud has the same length l . The i -th initially covers the range of (x_i, x_i + l) (endpoints excluded). Initially, it moves at a velocity of v_i , which equals either 1 or -1 . Furthermore, no pair of clouds intersect initially, that is, for all 1 <= q i lt j <= q n , lvert x_i - x_j rvert geq l . With a wind velocity of w , the velocity of the i -th cloud becomes v_i + w . That is, its coordinate increases by v_i + w during each unit of time. Note that the wind can be strong and clouds can change their direction. You are to help Mino count the number of pairs (i, j) ( i < j ), such that with a proper choice of wind velocity w not exceeding w_ mathrm{max} in absolute value (possibly negative and/or fractional), the i -th and j -th clouds both cover the moon at the same future moment. This w doesn 't need to be the same across different pairs. The first line contains three space-separated integers n , l , and w_ mathrm{max} ( 1 <= q n <= q 10^5 , 1 <= q l, w_ mathrm{max} <= q 10^8 ) -- the number of clouds, the length of each cloud and the maximum wind speed, respectively. The i -th of the following n lines contains two space-separated integers x_i and v_i ( -10^8 <= q x_i <= q 10^8 , v_i in {-1, 1 } ) -- the initial position and the velocity of the i -th cloud, respectively. The input guarantees that for all 1 <= q i lt j <= q n , lvert x_i - x_j rvert geq l . Output one integer -- the'...