## Goal

Bob has a bathtub.

He wants to fill it with water but there are some leaks that let the water flow.

Given the dimensions `S` and `h` of the bathtub, the tap water `flow` and the `leakHeight` and `leakFlow` of each leak, calculate the `time`, rounded to the second down, Bob needs to fill his bathtub.

A leak does not leak the water flow until the water has reached the leak height.

The bathtub is a rectangular parallelepiped of surface area `S` and height `h`.
Input

**Line 1 :** An integer `S` for the surface area of the bathtub in cm².

**Line 2 :** An integer `h` for the height of the bathtub in cm.

**Line 3 :** An integer `flow` for the tap water flow in L/minute.

**Line 4 :** An integer `N` for the number of leaks.

`N` next lines : 2 space-separated integers `leakHeight` and `leakFlow` for the height of the leak in cm and the flow allowed by the leak (in L/minute).

Output

If the bathtub can be filled, output one line :

The `time`, in HH:MM:SS format, rounded to the second down, that Bob needs to fill his bathtub.

if the bathtub cannot be filled entirely, output one line :

Impossible, `filling height` cm.

Constraints

0≤`N`≤1000

0≤`leakHeight`<h

0<`time`≤99:59:59

0<`S`x`h`<2^32

Example

Input

12750
60
12
2
20 1
45 3