SPOJ in Gyumri

   Engineers working for Intellect Ltd. have proposed an innovative system to check the transfer of digital data. Only n-digit decimal numbers divisible by 11 are used during transfer. The system was implemented on a remote space station transferring data to Earth. Eventually, the mission control center received a message containing (n+1) digits. The analysis indicated that the message had an extra spurious digit.

   Write a program that will process the message and determine the number of ways to exclude a single digit so that the resulting number would be divisible by 11.

Limitations

   1 ≤ n ≤ 100 000.

Input

   The first line of the input file defines the message length n.

   The second line contains a decimal number having n+1 digits representing the mes- sage with an extra digit.

Output

   The number of ways to exclude a single digit as described above.

Example