# Probability

Time Limit: 3000/1000 MS (Java/Others)

Memory Limit: 32768/32768 K (Java/Others)

## Description

Mickey is interested in probability recently. One day , he played a game which is about probability with mini.First mickey gives a letter and a word to mini.Then mini calculate the probability that the letter appears in the word.For example,give you the letter "a" and the word "apple". the probability of this case is 0.20000.

## Input

The input contains several test cases. Each test case consists of a letter and a word.The length of the word is no longer than 200.

## Output

For each test case, print the probability rounded to five digits after the decimal point.

## Sample Input

a apple
c Candy
a banana

## Sample Output

0.20000
0.20000
0.50000

## Source

HDU 2007-11 Programming Contest_WarmUp