Question

This question is about football matches between teams. A record of games played between teams is stored in a graph G. Each edge in the graph corresponds to a match between a pair of teams. For example,
if there is an edge between vertices 3 and 6 then Team 3 has played a
match with Team 6.
Design and write down the pseudocode for the following algorithm.
Input: A[0..n−1, 0..n−1], an adjacency matrix for the graph G.
Output: A list of all pairs of teams that have not played a match
together.

can i get some help please i have no idea.