#include <iostream>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <sstream>
#include <cstdio>
#include <algorithm>
#include <stack>
#include <queue>
#include <cmath>
#include <iomanip>
#include <fstream>
using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    int n, k;
    cin >> n >> k;
    vector<int> v(n);
    for(int i = 0; i < n; ++i) {
        cin >> v[i];
    }
    sort(v.begin(), v.end());
    int ret = 0;
    for(int i = 0; i < (int) v.size(); ++i) {
        // for each i find the biggest number. such that their sum does not exceed x
        int left_bound = i + 1;
        int right_bound = (int) v.size() - 1;
        int it = -1;
        while(left_bound <= right_bound) {
            int middle = (left_bound + right_bound) / 2;
            if(v[middle] + v[i] <= k) {
                left_bound = middle + 1;
                it  = middle;
            }
            else {
                right_bound = middle - 1;
            }
        }
        if(it != -1) {
//            cout << v[i] << " " << v[it] << endl;
            v.erase(v.begin() + it);
            //erase(begin iterator, end iterator)
            //erase(specific iterator)
        }
        ++ret;
    }
    cout << ret << endl;

}
/*4 10
  1, 3, 7, 9


*/