Плохая погода

// OK http://contest.uni-smr.ac.ru/ru/problemset/6267/

# include <iostream>
# include <vector>
# include <set>

using namespace std;


bool check(vector<uint32_t> &m, size_t &mid, size_t &n, uint64_t &d) {
    multiset<uint64_t> q;
    bool is_good = true;
    for (size_t i = 0; i < mid; i++) {
        q.insert(m[i]);
    }
    for (size_t i = mid; i < n; i++) {
        size_t x = *q.begin();
        q.erase(q.begin());
        if (x + m[i] > d) {
            is_good = false;
            break;
        } else {
            q.insert(x + m[i]);
        }
    }
    return !is_good or *--q.end() > d;
}

int main() {
    size_t n;
    uint64_t d;
    cin >> n >> d;
    vector<uint32_t> m(n);
    for (size_t i = 0; i < n; i++) {
        cin >> m[i];
    }
    size_t left = 0;
    size_t right = n;
    while (right - left > 1) {
        size_t mid = (left + right) / 2;
        if (check(m, mid, n, d)) {
            left = mid;
        } else {
            right = mid;
        }
    }
    if (!check(m, right, n, d)) {
        cout << right;
    } else {
        cout << -1;
    }
    return 0;
}