Es demana implementar una màquina expenedora d'ampolles d'aigua.

El següent diagrama de flux explica el seu funcionament:

Input Format

En primer lloc un nombre enter indicant l'stock d'ampolles.

En segon lloc un nombre float indicant el preu de l'ampolla.

A continuació venen les operacions realitzades: INSERT, EXPEND, REFUND, OFF.

Constraints

-

Output Format

S'imprimiràn els següents missatges, en funció del workflow de la màquina:

• Balance:
• Insert coin
• Product unavailable
• Price:
• Refund:
• Your water, thanks

Test Case 1

Input

5
0.75

INSERT 1
EXPEND
REFUND
OFF

Output

Insert coin
Balance:1.0
Your water, thanks
Balance:0.25
Refund:0.25
Insert coin

Test Case 2

Input

5
0.75

INSERT 1
EXPEND
OFF

Output

Insert coin
Balance:1.0
Your water, thanks
Balance:0.25

Test Case 3

Input

5
0.75

INSERT 2
EXPEND
EXPEND
REFUND
OFF

Output

Insert coin
Balance:2.0
Your water, thanks
Balance:1.25
Your water, thanks
Balance:0.5
Refund:0.5
Insert coin

Test Case 4

Input

5
0.75

INSERT 0.5
EXPEND
INSERT 0.25
EXPEND
REFUND
OFF

Output

Insert coin
Balance:0.5
Price:0.75
Balance:0.5
Balance:0.75
Your water, thanks
Insert coin
Refund:0.0
Insert coin

Test Case 5

Input

2
1.5

INSERT 4.5
EXPEND
EXPEND
EXPEND
REFUND
OFF

Output

Insert coin
Balance:4.5
Your water, thanks
Balance:3.0
Your water, thanks
Balance:1.5
Product unavailable
Balance:1.5
Refund:1.5
Insert coin

Test Case 6

Input

1
0.5

EXPEND
INSERT 0.5
EXPEND
REFUND
EXPEND
OFF

Output

Insert coin
Price:0.5
Insert coin
Balance:0.5
Your water, thanks
Insert coin
Refund:0.0
Insert coin
Product unavailable
Insert coin

Test Case 7

Input

2
0.5

REFUND
EXPEND
INSERT 0.5
EXPEND
INSERT 0.25
REFUND
INSERT 0.75
EXPEND
EXPEND
REFUND
INSERT 0.25
OFF

Output

Insert coin
Refund:0.0
Insert coin
Price:0.5
Insert coin
Balance:0.5
Your water, thanks
Insert coin
Balance:0.25
Refund:0.25
Insert coin
Balance:0.75
Your water, thanks
Balance:0.25
Product unavailable
Balance:0.25
Refund:0.25
Insert coin
Balance:0.25

Test Case 8

Input

2
0.5

REFUND
EXPEND
INSERT 0.5
INSERT 0.5
EXPEND
INSERT 0.25
REFUND
INSERT 0.75
EXPEND
REFUND
REFUND
INSERT 0.25
REFUND
OFF

Output

Insert coin
Refund:0.0
Insert coin
Price:0.5
Insert coin
Balance:0.5
Balance:1.0
Your water, thanks
Balance:0.5
Balance:0.75
Refund:0.75
Insert coin
Balance:0.75
Your water, thanks
Balance:0.25
Refund:0.25
Insert coin
Refund:0.0
Insert coin
Balance:0.25
Refund:0.25
Insert coin