Sum Until First Zero

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Read integers in order and sum all values before the first zero. The zero is a terminator and is not included in the sum. Print the sum even if the first value is zero.

Input

A sequence ending with zero; no earlier value is zero. At most $10^5$ values precede the terminator.

Output

Print the sum of all integers preceding the zero; the result fits in signed 64-bit integer.

Subtasks

• Subtask 1 (20%): At most 5 values before zero, each with absolute value at most 10.
• Subtask 2 (30%): At most 100 values before zero, each with absolute value at most 1000.
• Subtask 3 (50%): At most $10^5$ values before zero, each with absolute value at most $10^6$.

Examples

Example 1

Input

5 -2 0

Output

3

Explanation

Add 5 then -2 to obtain 3; the zero ends the sequence.

Example 2

Input

0

Output

0

Explanation

The first value is the terminator; the sum remains zero.