Minimum Fuel Required

You are given several depots, each with a number of trucks. For each depot (test case), the first line contains three integers N, D, and F where:

• N is the number of trucks in the depot.
• D is the distance factor (in kilometers) each truck needs to travel.
• F is the fuel consumption multiplier.

Following this, there are N lines, each containing two integers: the capacity of a truck and the cargo amount it needs to carry. A truck can only be dispatched if the cargo does not exceed its capacity. The fuel required for a truck is computed as \[ \text{cargo} \times D \times F \] . The task is to determine the total fuel required to dispatch all trucks of each depot. If any truck in a depot cannot be dispatched (i.e. its cargo exceeds its capacity), then the result for that depot is "Impossible".

Note:

• If there are no trucks (N = 0), the total fuel required is considered as 0.

inputFormat

The input is read from stdin and is formatted as follows:

T
N1 D1 F1
capacity1,1 cargo1,1
capacity1,2 cargo1,2
... (N1 lines for test case 1)
N2 D2 F2
capacity2,1 cargo2,1
... (N2 lines for test case 2)
...

Where T is the number of test cases.

outputFormat

For each test case, output a single line on stdout:

• If all trucks can be dispatched, print the total fuel required (i.e. the sum of cargo \(\times\) D \(\times\) F for each truck).
• If any truck's cargo exceeds its capacity, print Impossible.

## sample

2
3 500 2
1000 450
1200 500
1500 300
2 700 1
1100 1200
900 800

1250000
Impossible

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