Problem Statement

The country of Yukikoda has national routes numbered starting from 1.
So that national routes can be told apart, no two national routes have the same number.
First, National Route 1 starts from Yukikoda Castle.
Every national route eventually branches into a left road and a right road.
National routes branch starting from the smaller-numbered national routes, using the smallest numbers available.
When branching, the left national route always has a smaller number than the right national route.
Route 1 branches into Route 2 on the left and Route 3 on the right.
Route 2 branches into Route 4 on the left and Route 5 on the right.
Route 3 branches into Route 6 on the left and Route 7 on the right.
Route 4 branches into Route 8 on the left and Route 9 on the right.
Route 5 branches into Route 10 on the left and Route 11 on the right.
National routes are numbered according to these rules.

Now, A-kun has left Yukikoda Castle and passed through some branch points without ever turning back.
A-kun remembers, in order, whether he took the left or the right at each branch.
Determine which route A-kun is currently walking on.

Input

S

A string S representing the directions taken at the branches is given.
S is a string of at least 0 and at most 30 characters consisting of the characters 'L' and 'R'.
'L' means moving left at a branch point, and 'R' means moving right.
The beginning of the string is A-kun's oldest memory, and the memories become newer in order.

A newline is always present at the end, so it is never the case that nothing at all is given, even for a string of 0 characters.

Output

Output on one line the number of the national route A-kun is walking on.
Do not forget the newline.

Sample

LR

5

RLL

12

RLLRLRLRRRLRL

12986

1