#include <stdio.h>
#include <algorithm>
#include <vector>

typedef long long int ll;

int main(void) {
    int array_len;
    ll x;
    scanf("%d%lld", &array_len, &x);
    std::vector<int> a;

    for (int i = 0; i < array_len; ++i) {
        int temp = 0;
        scanf("%d", &temp);
        a.push_back(temp);
    }

    std::sort(a.begin(), a.end());

    int count = 0;
    for (int i = 0; i < array_len; i++) {
        int tgt = x - a[i];
        if (std::binary_search(a.begin(), a.end(), tgt)) {
            int j = 1;
            count++;
            while (a[i + j] == tgt) {
                j++;
                count++;
            }
        }
    }
    printf("%d\n", count);
}