class MinHeap:
    def __init__(self):
        self.size = 0
        self.array = []

    def lchild(self, i):
        if i == 0:
            return heap.array[1]
        else:
            try:
                return heap.array[2*i+1]
            except IndexError:
                return None

    def rchild(self, i):
        if i == 0:
            return heap.array[2]
        else:
            try:
                return heap.array[2*i+2]
            except IndexError:
                return None

    def father(self, i):
        if i == 1 or i == 2:
            return heap.array[0]
        elif i == 0:
            return None
        elif i % 2 == 0:
            try:
                return heap.array[i/2-1]
            except IndexError:
                return None
        else:
            try:
                return heap.array[i//2]
            except IndexError:
                return None

def is_canonical_min_heap(heap):
    if heap.size == 0 or heap.size == 1:
        return True
    for i in range(heap.size):
        if self.lchild(i) is None and self.rchild(i) is None:
            pass
        if self.lchild(i) > self.rchild(i):
            return False
    return True

def canonise_min_heap(heap):
    for i in range(heap.size):
        lc = self.lchild(i)
        rc = self.rchild(i)
        fr = self.father(i)
        if fr is None:
            pass
        else:
            if heap.array[i] > fr:
                heap.array[i], fr == fr, heap.array[i]
                i = 0
        if lc is None and rc is None:
           pass
        else:
            if lc > rc:
                lc, rc = rc, lc