Sums
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Eric also went to the dentist.  Each time the dentist sees a patient,
she writes down the amount of money that she charges on a list
and yells ka-ching!!!

Sometimes, when she has a break between patients, the dentist wants 
to know how much money she has made within a certain period of time.
Your task is to write a programme to assist her.

Input
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The input consists of a list of n amounts (in dollars) a_1 ... a_n.  
Each amount appears by itself on a line and will have exactly two 
digits after the decimal (to indicate cents).  The end of the list 
of amounts is indicated by a 0.

Then, there are a list of queries, one per line.  Each query is
a pair of integers i and j, separated by a space, where 
1 <= i <= j <= n.  The end of the queries will be indicated
by a line containing 0 0, and no output should be produced for
this line.

n will be at most 500 000, and each amount a_i will be at most 1000.
There will be at most a million queries.

Output
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For each query pair i j, output on a separate line the sum of
amounts a_i + a_{i+1} + ... + a_j.  The amount should be shown
with two digits after the decimal point.

Sample Input
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134.23
23.10
99.99
0
1 3
2 3
2 2
0 0

Sample Output
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257.32
123.09
23.10