Short Program

TimeLimit:2000MS  MemoryLimit:256MB
64-bit integer IO format:%I64d
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Problem Description

Petya learned a new programming language CALPAS. A program in this language always takes one non-negative integer and returns one non-negative integer as well.

In the language, there are only three commands: apply a bitwise operation AND, OR or XOR with a given constant to the current integer. A program can contain an arbitrary sequence of these operations with arbitrary constants from 0 to 1023. When the program is run, all operations are applied (in the given order) to the argument and in the end the result integer is returned.

Petya wrote a program in this language, but it turned out to be too long. Write a program in CALPAS that does the same thing as the Petya's program, and consists of no more than 5 lines. Your program should return the same integer as Petya's program for all arguments from 0 to 1023.

题意:按顺序给出n个位运算操作,问你是否能用5个以内的位运算等价替代这n个位运算(一定有解)

Input

The first line contains an integer n (1 ≤ n ≤ 5·105) — the number of lines.

Next n lines contain commands. A command consists of a character that represents the operation ("&", "|" or "^" for AND, OR or XOR respectively), and the constant xi 0 ≤ xi ≤ 1023.

Output

Output an integer k (0 ≤ k ≤ 5) — the length of your program.

Next k lines must contain commands in the same format as in the input.

SampleInput 1
3
| 3
^ 2
| 1
SampleOutput 1
2
| 3
^ 2
SampleInput 2
3
& 1
& 3
& 5
SampleOutput 2
1
& 1
SampleInput 3
3
^ 1
^ 2
^ 3
SampleOutput 3
0
Note

You can read about bitwise operations in https://en.wikipedia.org/wiki/Bitwise_operation.

Second sample:

Let x be an input of the Petya's program. It's output is ((x&1)&3)&5 = x&(1&3&5) = x&1. So these two programs always give the same outputs.

Submit
题目统计信息详细
总AC数35
通过人数28
尝试人数31
总提交量70
AC率40.00%
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