#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
#define pii pair<int, int>
void solve();

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int T = 1;
//    cin >> T;
    while (T--)solve();
    return 0;
}
#define LL __int128
void solve() {
    int n,m;
    cin>>n>>m;
    vector<int>a(n+1);
    vector<LL>pre(n+1);
    for(int i=1;i<=n;i++){
        cin>>a[i];
        pre[i]=pre[i-1]+a[i];
    }
    for(int i=1;i<=n;i++){
        LL x=pre[i-1]+(i)*(a[i]-1);
        if(x>=m){
            cout<<i-1<<endl;
            return;
        }
    }
    cout<<n<<endl;
}