The Mystery of Primes

let the series $a_1,a_2,a_3,a_4 ...$ , be the series of prime numbers starting with 3.

What will be that value of the infinite series (1 ■ $\frac{1}{a_1}$ )(1 ■ $\frac{1}{a_2}$ )(1 ■ $\frac{1}{a_3}$ )... given these rules

You must fill the black square with the appropriate sign according to these rules:

1) if the value of $a_n$ can be represented by 4k+1 where k is a positive integer, replace the black box with a PLUS sign

2) if not then replace the black box with a MINUS sign

Shown below are the first 3 terms of the infinite series (1- $\frac{1}{3}$ )(1+ $\frac{1}{5}$ )(1- $\frac{1}{7}$ )

The value of the infinite series (1 ■ $\frac{1}{a_1}$ )(1 ■ $\frac{1}{a_2}$ )(1 ■ $\frac{1}{a_3}$ )... can be represented as $\frac{x}{y}$ where x and y are real numbers and $\frac{x}{y}$ is in lowest terms. What is the value of [x+y]?

[x] represents the greatest integer function.