NewNode = {}
newNode[‘data’] = Head[‘data’]
newNode[‘next’] = None
ptr = Head
count = 0
while count < 3 and ptr != None:
   ptr = ptr[‘next’]
   count = count + 1
if ptr != None:
   newNode[‘next’] = ptr[‘next’]
   ptr[‘next’] = newNod

ptr = Head
while ptr[‘data’]  != 25:
   ptr[‘data’] = 0
   ptr = ptr[‘next’]