#include <bits/stdc++.h>

using namespace std;
using ll = long long;

const int N = 1e5 + 10;
const ll INF = 2e18;

int n;
ll p, a[N];

bool Check(int x) {
    ll mmin = a[x + 1];
    __int128 tp = 0;
    for (int i = x; i >= 1; i--) {
        mmin = min(mmin, a[i]);
        tp += mmin + a[i] - 1;
    }
    return tp + 2 * a[x + 1] - 1 >= p;
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    cin >> n >> p;
    for (int i = 1; i <= n; i++) cin >> a[i];
    int l = 1, r = n;
    while (l < r) {
        int mid = (l + r) >> 1;
        Check(mid) ? r = mid : l = mid + 1;
    }
    cout << l;
    return 0;
}