#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<ll>;
const ll INF = LLONG_MAX / 4;
#define rep(i, a, b) for(ll i = a; i < (b); i++)
#define all(a) begin(a), end(a)
#define sz(a) ssize(a)
bool chmin(auto& a, auto b) { if(a <= b) return 0; a = b; return 1; }
bool chmax(auto& a, auto b) { if(a >= b) return 0; a = b; return 1; }

int main() {
    cin.tie(0)->sync_with_stdio(0);
    ll n, p;
    cin >> n >> p;
    cout << [&]() -> ll {
        ll sum = 0;
        rep(i, 0, n) {
            ll x;
            cin >> x;
            if(sum + (i + 1) * (x - 1) >= p) return i;
            sum += x;
        }
        return n;
    }() << endl;
}