#include <stdio.h>

int main(void)
{
    int n, c;
    scanf("%d %d", &n, &c);

    int nums[n];
    for (int i = 0; i<n; i++)
    {
        scanf("%d", &nums[i]);
    }
    int a, b;
    int cnt = 0;
    int mem[n][n];
    for (int i = 0; i<n; i++)
    {
        for (int j = 0; j<n; j++)
        {
            mem[i][j] = 0;
        }
    }


    for (int i = 0; i<n; i++)
    {
        a = nums[i];
        b = a-c;
        if (b<0)
        {
            continue;
        }

        for (int j = 0; j<n; j++)
        {
            if (i == j || mem[i][j])
            {
                continue;
            }
            if (nums[j] == b)
            {
                cnt++;
                mem[i][j] = 1;
            }
        }
    }
    
    printf("%d", cnt);

    return 0;
}