[BOJ 10684] Shipura

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Points: 1
Time limit: 8.0s
Memory limit: 512M

Problem types
Allowed languages
Assembly, Awk, C, C++, Java, Pascal, Perl, Python, Sed, Text

Dr. Suposupo developed a programming language called Shipura. Shipura supports only one binary operator ({\tt >>}) and only one unary function ({\tt S<\ >}).</p>

(x {\tt >>} y) is evaluated to (\lfloor x / 2^y \rfloor) (that is, the greatest integer not exceeding (x / 2^y)), and ({\tt S<} x {\tt >}) is evaluated to (x^2 \bmod 1{,}000{,}000{,}007) (that is, the remainder when (x^2) is divided by (1{,}000{,}000{,}007)).

The operator ({\tt >>}) is left-associative. For example, the expression (x {\tt >>} y {\tt >>} z) is interpreted as ((x {\tt >>} y) {\tt >>} z), not as (x {\tt >>} (y {\tt >>} z)). Note that these parentheses do not appear in actual Shipura expressions.

The syntax of Shipura is given (in BNF; Backus-Naur Form) as follows:

expr   ::= term | expr sp ">>" sp term
term   ::= number | "S" sp "<" sp expr sp ">"
sp     ::= "" | sp " "
number ::= digit | number digit
digit  ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"

The start symbol of this syntax is (\tt expr) that represents an expression in Shipura. In addition, (\tt number) is an integer between (0) and (1{,}000{,}000{,}000) inclusive, written without extra leading zeros.

Write a program to evaluate Shipura expressions.

입력 형식

The input is a sequence of datasets. Each dataset is represented by a line which contains a valid expression in Shipura.</p>

A line containing a single ({\tt #}) indicates the end of the input. You can assume the number of datasets is at most (100) and the total size of the input file does not exceed (2{,}000{,}000) bytes.

출력 형식

For each dataset, output a line containing the evaluated value of the expression.

예제 입력

S< S< 12 >> 2 > >
123 >> 1 >> 1
1000000000   >>129
S<S<S<S<S<2>>>>>
S  <S< S<2013    >>> 11 >>> 10 >
#

예제 출력

81
30
0
294967268
14592400

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