Sum of dependencies in a graph

Given a directed and connected graph with n nodes. If there is an edge from u to v then u depends on v. Our task was to find out the sum of dependencies for every node.
Example: 
For the graph in diagram, 
A depends on C and D i.e. 2 
B depends on C i.e. 1 
D depends on C i.e. 1 
And C depends on none. 
Hence answer -> 0 + 1 + 1 + 2 = 4

Sum of dependencies in a graph: https://www.geeksforgeeks.org/sum-dependencies-graph/