//code_board
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef double db;
typedef pair<int,int> pa;
typedef vector<int> vec;
typedef string str;

const int bias = 5;

int T = 1;

void solve(){
    ll n, p;
    cin >> n >> p;
    vector<ll> a(n);
    for(ll i = 0; i < n; i++) cin >> a[i];
    ll sum = 0;
    for(ll i = 0; i < n; i++){
        if(p > sum + (i + 2) * (a[i] - 1)){
            sum += a[i];
        }else{
            cout << i << endl;
            return;
        }
    }
    cout << n << endl;
}

int main(){

//  freopen(".in","r",stdin);
//  freopen(".out","w",stdout);    
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    // cin >> T;
    while(T--) solve();

    return 0;
}