Write a program that reads a sequence of integer numbers and prints how many of them are equal to the sum of all the elements which are behind them.

Input

Input is a sequence of integer numbers.

Output

In a line, print the number of integer numbers of the input sequence that are equal to the sum of all the elements which are behind them.

Observation

Use recursion (not tables).

Public test cases

**Input**

-34 11 7 2 -8 5 3 2

**Output**

3

**Input**

4 2 2 0

**Output**

3

**Input**

**Output**

0

**Input**

0 32 -16 -8 -4 -2 -2

**Output**

5

**Input**

28 32 -5 9

**Output**

0

Information

- Author
- Jordi Petit
- Language
- English
- Translator
- Carlos Molina
- Original language
- Catalan
- Other languages
- Catalan
- Official solutions
- C++
- User solutions
- C++ Haskell Python