Problem:
Score : 200 points

Problem Statement

There are N points in a D-dimensional space.

The coordinates of the i-th point are (X_{i1}, X_{i2}, ..., X_{iD}).

The distance between two points with coordinates (y_1, y_2, ..., y_D) and (z_1, z_2, ..., z_D) is \sqrt{(y_1 - z_1)^2 + (y_2 - z_2)^2 + ... + (y_D - z_D)^2}.

How many pairs (i, j) (i < j) are there such that the distance between the i-th point and the j-th point is an integer?

Constraints

All values in input are integers.

2 \leq N \leq 10

1 \leq D \leq 10

-20 \leq X_{ij} \leq 20

No two given points have the same coordinates. That is, if i \neq j, there exists k such that X_{ik} \neq X_{jk}.

Input

Input is given from Standard Input in the following format:

N D
X_{11} X_{12} ... X_{1D}
X_{21} X_{22} ... X_{2D}
\vdots
X_{N1} X_{N2} ... X_{ND}

Output

Print the number of pairs (i, j) (i < j) such that the distance between the i-th point and the j-th point is an integer.

Sample Input 1

3 2
1 2
5 5
-2 8

Sample Output 1

1

The number of pairs with an integer distance is one, as follows:

The distance between the first point and the second point is \sqrt{|1-5|^2 + |2-5|^2} = 5, which is an integer.

The distance between the second point and the third point is \sqrt{|5-(-2)|^2 + |5-8|^2} = \sqrt{58}, which is not an integer.

The distance between the third point and the first point is \sqrt{|-2-1|^2+|8-2|^2} = 3\sqrt{5}, which is not an integer.

Sample Input 2

3 4
-3 7 8 2
-12 1 10 2
-2 8 9 3

Sample Output 2

2

Sample Input 3

5 1
1
2
3
4
5

Sample Output 3

10

Solution in C (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <string.h>

int is_double(char str[100][11], int N, int x)
{
	int i = 0;
	while (i < N)
	{
		if (i != x && strcmp(str[i], str[x]) == 0)
			return 1;
		i++;
	}
	return 0;
}

int main()
{
	int N;
	scanf("%d", &N);
	char s[N][11];
	int len[N];
	int i = 0;
	while (i < N)
	{
		scanf("%s", s[i]);
		len[i] = strlen(s[i]);
		i++;
	}
	i = 0;
	int j;
	while (i < N)
	{
		j = 0;
		while (j < N)
		{
			if (i != j && strcmp(s[i], s[j]) == 0)
			{
				printf("No\n");
				return 0;
			}
			j++;
		}
		if (i != N-1 && s[i][len[i] - 1] != s[i+1][0])
		{
			printf("No\n");
			return 0;
		}
		// printf("%d\n", len[i]);
		i++;
	}
	printf("Yes\n");
	return (0);
}