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

#define tsolve int t; cin >> t; while(t--) solve
#define debug(x) cerr << __LINE__ << ": "#x" = " << (x) << endl
#define all(x) ::begin(x), ::end(x)
#define sz(x) (int)::size(x)
using ll = long long;
using ld = long double;

void solve() {
	ll n, p;
	cin >> n >> p;

	vector<ll> a(n);
	for (ll& e : a) cin >> e;

	int ans = n;
	ll sm = 0;
	for (ll i=0; i<n; i++) {
		ll x = (i+1) * (a[i]-1) + sm;
		if (x >= p) {
			ans = i;
			break;
		}
		sm += a[i];
	}

	cout << ans << '\n';
}

int main() {
	cin.tie(0)->sync_with_stdio(false);
	cout << setprecision(16);
	solve();
}