from typing import List


def gen_graph_out(size: int, value: int = -1, diagonal: int =-1) -> List:
    """ Generate graph output

    :param size: size of graph
    :param value: value for each cell
    :param diagonal: value for diagonal cells
    """
    graph = [[value] * size for _ in range(size)]
    if diagonal != value:
        for i in range(size):
            graph[i][i] = diagonal
    return graph