#include <iostream>
#include <vector>
#include <map>
#include <algorithm>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n;
    long long k;
    if (!(cin >> n >> k)) return 0;

    map<long long, int> last_pos;
    last_pos[0] = 0;
    long long sum = 0;
    int min_len = 1e9;

    for (int i = 1; i <= n; ++i) {
        long long x;
        cin >> x;
        sum += x;
        if (last_pos.count(sum - k)) {
            min_len = min(min_len, i - last_pos[sum - k]);
        }
        last_pos[sum] = i;
    }

    cout << (min_len > n ? -1 : min_len) << "\n";
    return 0;
}