The Wolf and the Hare#3272
A straight road is given, on which a Wolf and a Hare are located. At the initial moment, the Wolf is at point X_1, and the Hare is at point X_2. They start moving simultaneously: the Wolf at a speed of m/s, and the Hare at a speed of cm/s. Determine the time in seconds when they will meet.
Four real numbers are given: , , X_1, X_2 (|X_1 - X_2| \leq 10^3, and the absolute values of and do not exceed 5 \times 10^2). If or is less than , the corresponding animal moves in the direction of decreasing coordinate; if greater than , in the direction of increasing .
Print the time in seconds when they will meet, or if they will never meet. The answer must be given with a precision of decimal places.
Example 1