def METHOD_NAME(n, delta_k=None, delta_r=0.0):
    G = MNA(n)
    G.add_d(n-1, 1)
    t0 = time.perf_counter_ns()
    for i in range(n):
        G.add_r(i-1, i, 1+delta_r if delta_k is not None and i == delta_k else 1)
        G.add_c(i, 1)
    t1 = time.perf_counter_ns()
    print(f'build: {(t1-t0)/1e9}')
    G.semantic()
    return G