#D11809. String Set

    ID: 9822 Type: Default 2000ms 268MiB

String Set

String Set

Problem statement

Of the string set S S that meets the following conditions, configure 1 1 with the largest number of elements.

  • The length of the string contained in S S is 1 1 or more and N N or less.
  • The lengths of the strings contained in S S are different.
  • The string contained in S S consists only of the characters 0 and 1.
  • For any 2 2 string contained in S S , one is not a substring of the other.

However, the substring of the string x x is the string obtained by removing more than 0 0 characters from the beginning and end of x x .

Constraint

  • 1 leqN leq300 1 \ leq N \ leq 300
  • N N is an integer

input

Input is given from standard input in the following format.

N N

output

Output 1 1 of the string set S S that satisfies the condition with the maximum number of elements. There may be multiple such S S , but any output will be correct.

Specifically, output in the following format.

Output K K , the number of elements of S S , on the 1 1 line.

Output all S S elements from the 2 2 line to the K+1 K + 1 line. Print 1 1 of S S elements on each line.

K K S1 S_1 S2 S_2  vdots \ vdots SK S_K


Input example 1

2

Output example 1

2 0 11

The string set 0,11 \\ {0, 11 \\} is the set with the largest number of elements that meets the conditions.


Input example 2

1

Output example 2

1 0

Example

Input

2

Output

2 0 11

inputFormat

input

Input is given from standard input in the following format.

N N

outputFormat

output

Output 1 1 of the string set S S that satisfies the condition with the maximum number of elements. There may be multiple such S S , but any output will be correct.

Specifically, output in the following format.

Output K K , the number of elements of S S , on the 1 1 line.

Output all S S elements from the 2 2 line to the K+1 K + 1 line. Print 1 1 of S S elements on each line.

K K S1 S_1 S2 S_2  vdots \ vdots SK S_K


Input example 1

2

Output example 1

2 0 11

The string set 0,11 \\ {0, 11 \\} is the set with the largest number of elements that meets the conditions.


Input example 2

1

Output example 2

1 0

Example

Input

2

Output

2 0 11

样例

2
2

0 11

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