#include <iostream>
#include <vector>

using namespace std;

int main() {
    cin.sync_with_stdio(false);
    cin.tie(nullptr);

    int N, P;
    cin >> N >> P;
    vector<int> payS(N);
    for (auto &e : payS) {
        cin >> e;
    }
    int minimum = -1;
    for (int l = 0, r = 0, current = 0; l < N; l++) {
        while (r < N && current < P) {
            current += payS[r++];
        }
        if (current >= P && (minimum == -1 || r - l < minimum)) {
            minimum = r - l;
        }
        current -= payS[l];
    }
    cout << minimum << '\n';
}