{"raw_statement":[{"iden":"statement","content":"Kotori is interested in skiing. The skiing field is an infinite strip going along $y$-axis on the 2-dimensional plane where all points $(x, y)$ in the field satisfies $-m \\le x \\le m$. When skiing, Kotori cannot move out of the field, which means that the absolute value of his $x$-coordinate should always be no more than $m$. There are also $n$ segments on the ground which are the obstacles and Kotori cannot move across the obstacles either.\n\nKotori will start skiing from $(0, -10^{10^{10^{10^{10}}}})$ (you can regard this $y$-coordinate as a negative infinity) and moves towards the positive direction of the $y$-axis. Her vertical (parallel to the $y$-axis) speed is always $v_y$ which cannot be changed, however she can control her horizontal (parallel to the $x$-axis) speed in the interval of $[-v_x, v_x]$. The time that Kotori changes her velocity can be neglected.\n\nYour task is to help Kotori calculate the minimum value of $v_x^*$ that once $v_x>v_x^*$ she can safely ski through the skiing field without running into the obstacles."},{"iden":"input","content":"There is only one test case in each test file.\n\nThe first line of the input contains three positive integers $n$, $m$ and $v_y$ ($1 \\le n \\le 100$, $1 \\le m \\le 10^4$, $1 \\le v_y \\le 10$), indicating the number of obstacles, the half width of the skiing field and the vertical speed.\n\nFor the following $n$ lines, the $i$-th line contains four integers $x_1$, $y_1$, $x_2$ and $y_2$ ($-m \\le x_1, x_2 \\le m$, $-10^4 \\le y_1, y_2 \\le 10^4$, $x_1 \\ne x_2$ or $y_1 \\ne y_2$) indicating the $i$-th obstacle which is a segment connecting point $(x_1, y_1)$ and $(x_2, y_2)$, both inclusive (that is to say, these two points are also parts of the obstacle and cannot be touched). It's guaranteed that no two obstacles intersect with each other."},{"iden":"output","content":"Output one line containing one number indicating the minimum value of $v_x^*$. If it is impossible for Kotori to pass through the skiing field, output ``-1`` (without quotes) instead.\n\nYour answer will be considered correct if and only if its absolute or relative error does not exceed $10^{-6}$."}],"translated_statement":null,"sample_group":[["3 2 1\n-2 0 1 0\n-1 4 2 4\n0 1 0 3","1.000000000000000"],["2 1 2\n-1 0 1 0\n1 1 0 1","-1"],["2 3 7\n-3 0 2 2\n3 1 -2 17","1.866666666666666"],["1 100 1\n-100 0 99 0\n","0.000000000000000"]],"show_order":[],"formal_statement":null,"simple_statement":null,"has_page_source":false}