def second_smallest(numbers):  
    a1, a2 = float('inf'), float('inf')  
    for x in numbers:  
        if x <= a1:  
            a1, a2 = x, a1  
        elif x < a2:  
            a2 = x  
    return a2  
print(second_smallest([1, 2, -8, -2, 0]))