Sum with Unlucky 13

Background

Congcong is playing a number game. He needs to calculate the sum of a series of numbers, but some numbers are considered unlucky and require special handling.

Problem Description

Return the sum of the numbers in the array, returning $0$ for an empty array.

Except the number $13$ is very unlucky, so it does not count and numbers that come immediately after a $13$ also do not count.

Input Format

Input is given from Standard Input in the following format.

A single line containing multiple integers, representing the elements of the array.

Output Format

Output is to be printed to Standard Output in the following format.

A single integer, representing the calculated sum.

Sample

1 2 2 1

6

1 1

2

1 2 2 1 13

6

Sample Explanation

For the sample input 1 2 2 1 13: The numbers in the array are $1, 2, 2, 1, 13$. $1$ is counted. Current sum: $1$. $2$ is counted. Current sum: $1+2=3$. $2$ is counted. Current sum: $3+2=5$. $1$ is counted. Current sum: $5+1=6$. $13$ is unlucky and not counted. The final sum is $6$.

Constraints

Time limit: $1$ second, Memory limit: $1024$ KiB for each test case.