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

using namespace std;

struct PartSum{
    int value;
    int idx;
};

bool operator <(const PartSum& lhs, const PartSum& rhs) {
    if (lhs.value == rhs.value) {
        return lhs.idx < rhs.idx;
    }
    return lhs.value < rhs.value;
}

void FindSubarray(const vector<int> v, int x) {
    int n = v.size();
    if (n == 0) {
        cout << "Empty array" << endl;
        return;
    }
    vector<int> v_copy(n + 1);
    for (int i = 1; i <= n; ++i) {
        v_copy[i] = v[i - 1];
    }

    vector<int> part_sum(n + 1);
    part_sum[0] = 0;
    for (int i = 1; i <= n; ++i) {
        part_sum[i] = part_sum[i - 1] + v_copy[i];
    }

    vector<PartSum> ps(n + 1);
    for (int i = 0; i <= n; ++i) {
        ps[i] = {part_sum[i], i};
    }

    sort(ps.begin(), ps.end());

    /*
    for (int i = 0; i <= n; ++i) {
        cout << ps[i].value << " " << ps[i].idx << endl;
    }
    */

    int left = 0;
    int right = 1;
    while (right <= n) {
        int cur_diff = ps[right].value - ps[left].value;
        if (cur_diff > x) {
            left++;
        } else if (cur_diff < x) {
            right++;
        } else {
            if (ps[right].idx > ps[left].idx) {
                cout << "Subarray from "
                    << ps[left].idx + 1 << " to "
                    << ps[right].idx << " is OK" << endl;
                return;
            }
            right++;
        }
        if (left == right) {
            right++;
        }
    }
    cout << "Impossible" << endl;
}

int main() {
    FindSubarray({2, 1, 1, -1, -2}, 3);
    //FindSubarray({1, 2, 3, 4, 5}, -3);
    FindSubarray({1, 2, 3, 4, 5}, 15);
    FindSubarray({-1, -1, -1, 333, -5, +5, 444, -1, -1}, 777);
    FindSubarray({1, -1, 1, -1, 1}, 0);
    FindSubarray({1, -1, 1, -1, 1}, 1);
    //FindSubarray({1, -1, 1, -1, 1}, -1);
    FindSubarray({1, -1, 1, -1, 1}, 1);
    FindSubarray({1, -1, 1, -1, 1, -1}, 1);
    FindSubarray({-1, 1, -1, 1, -1, -1}, 1);
    FindSubarray({-1, 1, -1, 1, -1}, 1);
    FindSubarray({1, -1, 1, -1, 1}, 2);
    return 0;
}