N, S, K = map(int, input().split())
A = [int(input()) for _ in range(N)]
R, C = 0, K + 1
for T in range(N):
    if abs(A[T] - S) <= K and abs(A[T] - S) < C:
        C = abs(A[T] - S)
        R = T + 1
if R: print(R)
else: print("Unlucky!")