Description

Given a prefix expression, please evaluate its value.

The grammar of prefix expression could be defined as: EXPR := OP EXPR EXPR | CONSTANT, where OP is one of +, -, *, /, %. For division and modolus operations, we adapt C behavior, i.e., rounding to zero.

It's guaranteed that in each step of the calculation the value is always between [-2⁶³, 2⁶³).

Note

You can use atoi() to convert a string to integer.

Input

There's only one line containing the prefix expression. There are spaces between each operands and operators. Each number in the expression is no less than -2³¹ and less than 2³¹.

Output

Please print out the value of the expression. Remember to put a newline character at the end of line.

Sample Input  Download

Sample Output  Download

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