Problems

# Prefixes of a substring

# Prefixes of a substring

The prefix of a string **S** is any string of the form **S**[**1**..**k**], **k** ≤ size(**S**) (size(**S**) is the length of a string). Prefix can be either empty or match the string itself. If prefix is not empty and does not match with the string **S**, it is called the proper prefix of string **S**. Print the number of prefixes and all proper prefixes of substring **S**[**i**..**j**] in the increasing order of their lengths.

#### Input

First line contains **S**, its length is no more than **100**. Second line contains two indexes **i** and **j** (**1** ≤ **i** ≤ size(**S**), **1** ≤ **j** ≤ size(**S**)).

#### Output

Print in the first line the number of prefixes of substring **S**[**i**..**j**]. In the next lines print all proper prefixes of a given substring. The output format is given in a sample.

Input example #1

abracadabra 2 5

Output example #1

5 b br bra