URI Online Judge | 1093
# Vampires

**Timelimit: 1**

By Pedro Demasi Brazil

Felipinho is thrilled with his new RPG game, about wars between clans of vampires. In this game he plays a vampire that repeatedly comes into combat against vampires from other clans. Such battles are won or lost based on some characteristics of the opponents, with the help of a standard six-faced dice. For simplicity, we will consider only the fight between two vampires, Vampire 1 and Vampire 2. Each vampire has a vital energy (denoted respectively by *EV _{1}* and

The combat is fought in turns, in the following way. At each turn, the dice is rolled; if the result value is less than or equal to ** AT**, Vampire 1 wins the turn, otherwise Vampire 2 wins. The winner then sucks the value

For example, suppose * EV_{1}=7*,

Despite loving the game, Felipinho thinks that the combats are too long, and suspects that, given the initial values of ** EV_{1}**,

The input contains several test cases. Each test case is given in one single line, containing four integers ** EV_{1}**,

For each test case in the input, your program must print a single line. The line must contain a real number representing, in terms of percentages, the probability that Vampire 1 wins the combat. The result must be printed as a real number with exactly one decimal figure.

Input Sample | Output Sample |

1 1 3 1 |
50.0 |