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Time limit1.5sMemory limit4 MB

Summary

Maintain a set of integers 1 to 20 under add, remove, toggle, check, all, and empty, and print each check result.

Level: Easy3 of 10
Topics: Bit manipulation, Implementation
Solved: No attempts yet

Problem

You start with an empty set $S$ . Write a program that performs the following operations.

add x: adds $x$ to $S$ . If $x$ is already in $S$ , the operation is ignored.
remove x: removes $x$ from $S$ . If $x$ is not in $S$ , the operation is ignored.
check x: prints 1 if $x$ is in $S$ , and 0 otherwise.
toggle x: removes $x$ from $S$ if $x$ is in $S$ , and adds $x$ otherwise.
all: replaces $S$ with $\{1, 2, \ldots, 20\}$ .
empty: replaces $S$ with the empty set.

For add, remove, check and toggle, the argument satisfies $1 \le x \le 20$ .

Input

The first line contains the number of operations $M$ ( $1 \le M \le 3{,}000{,}000$ ).

Each of the next $M$ lines contains one operation. It is one of the six operations described above, and an operation that takes an argument has its name and $x$ separated by a single space.

Output

For every check operation, print its result on its own line, in the order the operations are given.

If there is no check operation, print nothing.

Examples1

Example 1

Input

26
add 1
add 2
check 1
check 2
check 3
remove 2
check 1
check 2
toggle 3
check 1
check 2
check 3
check 4
all
check 10
check 20
toggle 10
remove 20
check 10
check 20
empty
check 1
toggle 1
check 1
toggle 1
check 1

Expected output