The mutual arrangement of lines
No matter who N. sits at the point a a straight line and is able to crawl at a speed V. On the other, or the first line at the point b lies no matter what X., passionately desired N.
Help N. determine the time that he needed to get to X. Please note that N. at any time should remain one of the two lines.
Input
The input file contains 5 lines:
six numbers x_11, y_11, z_11, x_12, y_12, z_12 — the coordinates of two different points of the first direct
six numbers x_21, y_21, z_21, x_22, y_22, z_22 — the coordinates of two different points in the second line
three numbers a_1, b_1, c_1 — the coordinates of N.
three numbers a_2, b_2, c_2 — the coordinates of X.
V — velocity of N.
All numbers are integers, not exceeding modulo 10^6. Guaranteed that both N., and X. are each in one of the lines.
Output
Minimum time required N., to get to X. Result output with five characters after the decimal point. If N. reach X. not be able to output to the output file number "-1".