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

int main() {
    int n, w;
    cin >> n >> w;
    vector<int64_t> a(n), s(n + 1);
    for (int i = 0; i < n; i++) {
        cin >> a.at(i);
        s.at(i + 1) = s.at(i) + a.at(i);
    }
    int discard = 0, ans = 0;
    set<int64_t> t;
    for (int i = 0; i < n; i++) {
        if (t.find(a.at(i)) == t.end()) {
            t.insert(a.at(i));
            while (s.at(i + 1) - s.at(discard) > w) {
                t.erase(a.at(discard));
                discard++;
            }
        } else {
            while (a.at(discard) != a.at(i)) {
                discard++;
            }
            discard++;
        }
        ans = max(ans, i + 1 - discard);
    }
    cout << ans << endl;
}