Consider the following Flow Network:

Consider the following Flow Network:               (1,2,20)               (1,3,20)               (1,4,15)               (2,5,14)               (3,4,25)               (3,5,16)               (4,6,16)               (4,7,14)               (5,6,11)               (5,7,12)               (6,7,15)               Note that each triple represents a weighted edge such that               the first number is the originating node, the second               the terminating node and the third its weight.         Task:        Write a well-structured program that does the following:1.    Find and print all topological orderings of nodes of the input Flow Network.2.    Find and print out an Optimal topological ordering.3.    Compute a Maximum Restrictive Cutset (which represents Minimum Total ) print all its edges along their respective loads (weights).    , print the the Total itself.         Requirement:        the efficiency purpose, your program must one            topological ordering finding the Maximum Restrictive Cutset.        unable one topological ordering, your program           must indicate so the comments.