import std;

void main() {
    int N, S, K;
    readf("%d %d %d\n", N, S, K);

    int res, diff = int.max;
    foreach (i; 0 .. N) {
        int A;
        readf("%d\n", A);

        int d = abs(A-S);
        if (d <= K && d < diff) {
            res = i + 1, diff = d;
        }
    }

    if (res == 0) writeln("Unlucky!");
    else res.writeln;
}