Taxi

Input

The first line contains five numbers: four integers and one real number:

• $n$ — the number of towns,

• $A$ — the number of the town where Ivan lives,

• $B$ — the number of the town where Sergey lives,

• $C$ — the number of the town where the olympiad takes place,

• $d$ — the cost of traveling one kilometer by taxi.

The second line contains an integer $m$ — the number of roads.

Then follow $m$ lines, each describing one road: two integers representing the towns the road connects, and one real number — the length of the road in kilometers.

All town numbers are positive integers not exceeding $100$.

Output

Print one real number — the extra cost of the trip if the taxi picks up Sergey, compared to going directly to the olympiad venue.

If there is no route from point $A$ to point $B$ or from point $A$ to point $C$, print $-1$.

Examples