Given a list, calculates the sum of all the elements in the list that precede the first 0. If the 0 is not present the result will be the sum of all the elements. If the list is empty, return 0.

NOTE: To read the input list you can, for example, use the lis = eval(input()) command which stores the input list in the lis variable.

Input

A list of number

Output

the sum of all the elements in the list that precede the first 0. If the 0 is not present the result will be the sum of all the elements. If the list is empty, return 0

Example

Input:
[3,6,7,2,0,4,0,45,32,0]

Output:
18