def itriplets(it):
    i = 1
    n1, n2, n3 = next(it), next(it), next(it)
    yield (n1, n2, n3, i)
    for n in it:
        n1, n2, n3 = n2, n3, n
        i += 1
        yield (n1, n2, n3, i)

def maxmin_locals(it):
    itt = itriplets(it)
    fi = False
    while not fi:
        try:
            t = next(itt)
            if t[0] > t[1] < t[2]:
                yield  'min', t[1], t[3]
            elif t[0] < t[1] > t[2]:
                yield 'max', t[1], t[3]
        except StopIteration:
            fi = True