#include <bits/stdc++.h>
using namespace std;

struct Interval {
    long long l;
    long long r;
};

struct Compare {
    bool operator()(const Interval& a, const Interval& b) const {
        long long size_a = a.r - a.l + 1;
        long long size_b = b.r - b.l + 1;
        if (size_a != size_b)
            return size_a < size_b; // max heap
        else
            return a.l > b.l; // tie-breaker
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    long long n, p;
    cin >> n >> p;
    // Read all c's
    vector<long long> c(n);
    for(auto &x: c) cin >> x;
    // Initialize priority queue
    priority_queue<Interval, vector<Interval>, Compare> pq;
    if(p >=1){
        pq.push(Interval{1, p});
    }
    long long count = 0;
    for(long long i=0;i<n;i++){
        long long current_c = c[i];
        // Check if any interval has size >= current_c
        while(!pq.empty()){
            Interval top = pq.top();
            long long size = top.r - top.l + 1;
            if(size >= current_c){
                // Can perform this trip
                pq.pop();
                count++;
                // Find the stamp position
                long long s = top.l + (size - current_c)/2;
                long long e = s + current_c -1;
                // Add left interval
                if(s > top.l){
                    pq.push(Interval{top.l, s-1});
                }
                // Add right interval
                if(e < top.r){
                    pq.push(Interval{e+1, top.r});
                }
                break;
            }
            else{
                // This interval is too small, remove it
                pq.pop();
            }
        }
        // After trying to perform the trip
        // Check if we performed it
        if(count < i+1){
            // Failed on this trip
            cout << count;
            return 0;
        }
    }
    // If all trips performed
    cout << count;
}