The jumping digits to letters transformation Imagine you have an infinite sequence of the alphabet repeated infinitely many times:

abcdefghijklmnopqrstuvwxyzabcd...


You start at index 0, which corresponds to the letter a, and the should_write boolean flag is False.

The input is a list or string of single-digit numbers. For each number n in the input, you should:


Print (or add to the return value) the n-th item of the list if the should_write flag is set to True
If n is 0, swap the should_write flag.
Otherwise move (jump) the index n places forward.


At the end of the input, stop (and return the result if using a function).

Input

A sequence of digits (list or string).

Output

The text that comes out after applying the above procedure.

Examples

&gt;&gt;&gt; g('99010')
st
&gt;&gt;&gt; g('100')
b
&gt;&gt;&gt; g('2300312')
f
&gt;&gt;&gt; g('390921041912042041010')
mvxyptvab
&gt;&gt;&gt; g('1')
&gt;&gt;&gt; g('1045')
bf
&gt;&gt;&gt; g('33005780')
g
&gt;&gt;&gt; g('100100102')
bcd
&gt;&gt;&gt; g('012')
ab
Python 3, 60



i=b=0
for c in input():b and print(chr(97+i%26));b^=c&lt;1;i+=c


Takes a list of numbers and prints the chars on separate lines.

Basically just follows the instructions. The index is i and the should_write flag is b. The expression b and short-circuits to print only when b is true.