def minimumDistances(a):
    # Write your code here
    values = []
    for i in a:
        start = a.index(i)
        if a.count(i) >= 2:
            #d=a.index(i, start+1)
            values.append(abs(a.index(i, start+1)-start))
            print(i)
    if values:
        return min(values)
    else:
        return -1