# Add and Divide

Given four non-zero integers $a$, $b$, $c$ and $d$. Calculate $\frac{ad+bc}{bd} \pmod{10^9+7}$.

## Input format
The input contains four integers $a$, $b$, $c$ and $d$ ($1 \le a, b, c, d \le 10^9$).

## Output format
Print one integer - the value of $\frac{ad+bc}{bd} \pmod{10^9+7}$.

### Sample 1

#### Input

1 2 2 4

#### Output

1

### Sample 2

#### Input

-1 3 1 2

#### Output

166666668