Set

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 $1 \le x \le 20$.

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.

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.