#D7729. Prime Quadruplet
Prime Quadruplet
Prime Quadruplet
A set of four prime numbers arranged like (a, a + 2, a + 6, a + 8) is called a quadruplet prime number. Of the four prime numbers that make up a quadruplet prime, the largest number is called the size of the quadruplet prime. For example, the smallest prime quadruplet is a set of (5, 7, 11, 13), which is 13 in size. The next largest prime quadruplet is the set of (11, 13, 17, 19), which is 19 in size.
Create a program that takes the integer n (13 ≤ n ≤ 10,000,000) as input and outputs the maximum size of the quadruplet prime numbers whose size is n or less.
Input
A sequence of multiple datasets is given as input. The end of the input is indicated by a single line of zeros. One integer n is given on one row for each dataset.
The number of datasets does not exceed 2000.
Output
Outputs the maximum prime quadruplet size on one line for each input dataset.
Example
Input
13 14 15 16 17 18 19 20 10000 0
Output
13 13 13 13 13 13 19 19 9439
inputFormat
input and
outputFormat
outputs the maximum size of the quadruplet prime numbers whose size is n or less.
Input
A sequence of multiple datasets is given as input. The end of the input is indicated by a single line of zeros. One integer n is given on one row for each dataset.
The number of datasets does not exceed 2000.
Output
Outputs the maximum prime quadruplet size on one line for each input dataset.
Example
Input
13 14 15 16 17 18 19 20 10000 0
Output
13 13 13 13 13 13 19 19 9439
样例
13
14
15
16
17
18
19
20
10000
0
13
13
13
13
13
13
19
19
9439
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