// {{{1
extern "C" int __lsan_is_turned_off() { return 1; }
#include <bits/stdc++.h>
using namespace std;

#include <tr2/dynamic_bitset>
using namespace tr2;
#include <ext/pb_ds/assoc_container.hpp>

#define ll long long
#define inf 0x3f3f3f3f
#define infl 0x3f3f3f3f3f3f3f3fll

#include <assert.h>
#ifdef DEBUG
#define dprintf(args...) fprintf(stderr,args)
#endif
#ifndef DEBUG
#define dprintf(args...) 69
#endif
#define all(x) (x).begin(), (x).end()
struct cintype { template<typename T> operator T() { T x; cin>>x; return x; } };
// 1}}}
cintype in;

int main()
{
        int n=in,k=in;
        vector<int> a(n);for(auto&x:a)x=in;

        sort(all(a));reverse(all(a));
        int turn=0;
        ll ans=0;
        for(auto x:a) {
                if(x<=k) {
                        if(turn==0) ans+=x;
                        turn^=1;
                }
        }
        while(a.size()&&a.back()<=k) a.pop_back();
        for(auto x:a)if(~x&1) {
                ans+=x/2;
                turn^=1;
        }
        for(auto x:a) if(x&1) {
                if(turn==0)ans+=x/2;
                else ans+=x/2+1;
                turn^=1;
        }
        printf("%lld\n",ans);
}