S-expression is a prefix notation invented for and popularized by the programming language Lisp. Your task is to evaluate some simple S-expressions. In this problem, S-expression is defined as: 1. An atom. a. A nonnegative integer. Its value is the value of the integer. b. A boolean value, true or false. Its value is the boolean value of itself. c. A variable, consisting of no more than 10 lower case letters, excluding reserved words "if", "let", "true" and "false". Its value is the value bound to the variable. If the varible is not bound yet, produce an error "Unbound Identifier". (See below for details) 2. ( f x ... ) a. one of the following 4 forms: ( + x y ) ( - x y ) ( * x y ) ( x y ) in which x and y are both S-expressions. To evaluate the S-expression, you need to first evaluate x then evaluate y. If the value of x or y is not an integer, produce an error "Type Mismatch". If both x and y are integers, its value is the their sum(x+y)difference(x-y)product(x*y)quotient(xy). The division is the same as the integer division ("" operator) in CC++JavaC#, truncated division. If the value of y is zero, produce an error: "Division By Zero". b. ( if a b c ) in which a, b and c are S-expressions. To evaluate the S-expression, you need to evaluate a at first. If the value of a is not a boolean value, produce an error: "Type Mismatch". If the value of a is true, evaluate b and the S-expression's value is the value of b. If the value of a is false, evaluate c and the S-expression's value is the value of c. Note that b or c may not be evaluated during the calculation. c. ( let ( x a ) b ) in which x is a variable consisting of no more than 10 lower case letters, excluding reserved words "if", "let", "true" and "false", a and b are S-expressions. To evaluate the S-expression, you need to first evaluate a. Then bind the value of a to the variable x and evaluate b. Binding means if variable x appears in b, its value is the value of a. The S-expression's value is the value of b. Note that if x is bound to another value in b, the outer binding is ineffective. For example the value of ( let ( x 1 ) ( let ( x 2 ) x ) ) is 2. d. one of the following 3 forms: ( x y ) ( = x y ) in which x and y are S-expressions. To evaluate the S-expression, you need to first evaluate x then evaluate y. If the value of x or y is not an integer, produce an error "Type Mismatch". If both x and y are integers, its value is a boolean value indicating whether x y or x = y is true. Given an S-expression, output its value. If an error occurs stop the evaluation and output the error.

输入描述:

The first line contains an integer T (1 The following T lines each contain an S-expression consisting of no more than 200 characters.It is guaranteed input S-expressions do not have any syntax error. The variables, parentheses, integers, true and false are seperated by at least one space.For 100% of the data the integers in the whole evaluation will not exceed 32bit signed integers.

输出描述:

For each testcase output the value of the S-expression or one of the three errors "Division By Zero", "Type Mismatch" and "Unbound Identifier" without quotes.