题库练习 Prime Matrix
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A8961 | Prime Matrix

时间限制1s
内存限制256MB
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题目描述

You've got an $n×m$ matrix. The matrix consists of integers. In one move, you can apply a single transformation to the matrix: choose an arbitrary element of the matrix and increase it by $1$ . Each element can be increased an arbitrary number of times.

You are really curious about prime numbers. Let us remind you that a prime number is a positive integer that has exactly two distinct positive integer divisors: itself and number one. For example, numbers 2, 3, 5 are prime and numbers 1, 4, 6 are not.

A matrix is prime if at least one of the two following conditions fulfills:

- the matrix has a row with prime numbers only;
- the matrix has a column with prime numbers only;

Your task is to count the minimum number of moves needed to get a prime matrix from the one you've got.

输入格式

The first line contains two integers $n,m$ $(1<=n,m<=500)$ — the number of rows and columns in the matrix, correspondingly.

Each of the following $n$ lines contains $m$ integers — the initial matrix. All matrix elements are positive integers. All numbers in the initial matrix do not exceed $10^{5}$ .

The numbers in the lines are separated by single spaces.

输出格式

Print a single integer — the minimum number of moves needed to get a prime matrix from the one you've got. If you've got a prime matrix, print 0.

输入输出样例

输入 #1
3 3
1 2 3
5 6 1
4 4 1
输出 #1
1
输入 #2
2 3
4 8 8
9 2 9
输出 #2
3
输入 #3
2 2
1 3
4 2
输出 #3
0
C++ 编辑器
输入
输出