Prefix to Postfix (prefix)

Problem Background

Special for beginners, ^_^

Problem Description

In everyday life we usually use infix expressions, but computers also use prefix and postfix expressions, whose meanings are as follows:

Prefix: write the operator first, then the first operand, then the second operand.

Postfix: write the first operand first, then the second operand, then the operator.

For example, the infix expression 3 + 4 is written as + 3 4 in prefix and 3 4 + in postfix; while (5 - 4) - 2 is - - 5 4 2 in prefix and 5 4 - 2 - in postfix.

Your task is to input a prefix expression and output the corresponding postfix expression.

Input Format

Input a prefix expression. The operators are only + and -; each operand is a single digit (0 to 9); operators and operands are separated by a single space, and the expression has no leading spaces. Every expression is valid, and there are no more than 20 operators.

Output Format

Output the corresponding postfix expression.

Sample Input

+ 3 4

Sample Output

3 4 +

Constraints

Time limit: 1s, memory limit: 1024KiB for each test case.