#include <bits/stdc++.h>

using namespace std;
const int N = 1e5 + 10;
typedef long long LL;
LL a[N], b[N], s[N];
LL n, m;
LL cnt;
int main() {
    freopen("city.in", "r", stdin);
    freopen("city.out", "w", stdout);
    cin >> n >> m;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i <= n; i++) cin >> b[i];

    for (int i = 1; i <= n; i++) {
        cnt += a[i];
        if (cnt >= m) {
            cout << b[i] << endl;
            return 0;
        }
    }
    return 0;
}