I. The Easiest Problem
time limit per test
1 second
memory limit per test
512 megabytes
input
standard input
output
standard output

During class, the teacher often says "Scan the QR code to sign in now."

Now, Gew wants to ask you how many lowercase English letters there are in this sentence.

Input

The input contains only one line, containing the sentence "Scan the QR code to sign in now."

Output

Output an integer, denoting the answer to the question.

Example
Input
Scan the QR code to sign in now.
Output
-1
Note

The output of the example is not correct. It's you who need to figure out the answer, and get a correct verdict.