Tạo danh sách cạnh

class Edge:
    def __init__(self, u, v):
        self.u = u
        self.v = v
    def __str__(self):
        return '{0} {1}'.format(self.u, self.v)

n = int(input())

adj_matrix = []
for i in range(n):
    new_row = list(map(int, input().split()))
    adj_matrix.append(new_row)

edge_list = []
for u in range(n):
    for v in range(u + 1, n):
        if adj_matrix[u][v] == 1:
            edge_list.append(Edge(u, v))

print(len(edge_list))
for edge in edge_list:
    print(edge)