Graphviz subgraph fixed width with unlimit height

Question

//input.dot

digraph G {
        graph [bb="0,0,10,1000"]
        node [width=1 height=0.5 fixedsize=true];
        1[shape=rectangle];
        2[shape=rectangle];
        3[shape=rectangle];
        4[shape=rectangle];
        5[shape=rectangle];
        6[shape=rectangle];
        7[shape=rectangle];
        8[shape=rectangle];
        9[shape=rectangle];
        10[shape=rectangle];
        11[shape=rectangle];
        12[shape=rectangle];
        13[shape=rectangle];
        14[shape=rectangle];
        15[shape=rectangle];
        16[shape=rectangle];
        17[shape=rectangle];
        18[shape=rectangle];
        19[shape=rectangle];
        20[shape=rectangle];
    }

//output.dot

digraph G {
    graph [bb="0,0,10,1000"];
    node [label="\N", width=1, height="0.5", fixedsize=true];
    graph [bb="0,0,403,374"];
    1 [shape=rectangle, pos="149,152"];
    2 [shape=rectangle, pos="219,208"];
    3 [shape=rectangle, pos="240,131"];
    4 [shape=rectangle, pos="128,243"];
    5 [shape=rectangle, pos="275,264"];
    6 [shape=rectangle, pos="107,96"];
    7 [shape=rectangle, pos="198,75"];
    8 [shape=rectangle, pos="289,75"];
    9 [shape=rectangle, pos="310,187"];
    10 [shape=rectangle, pos="184,299"];
    11 [shape=rectangle, pos="93,299"];
    12 [shape=rectangle, pos="58,187"];
    13 [shape=rectangle, pos="331,131"];
    14 [shape=rectangle, pos="331,320"];
    15 [shape=rectangle, pos="51,40"];
    16 [shape=rectangle, pos="37,243"];
    17 [shape=rectangle, pos="191,19"];
    18 [shape=rectangle, pos="282,19"];
    19 [shape=rectangle, pos="366,243"];
    20 [shape=rectangle, pos="240,355"];
}

How to set the bb for the graphviz with fixed size components

I have run this command

neato -T dot -o output.do input.dot

it seem the cannot fixed the width of the page

graph [size"10,1000"] is not wanted, I need a fixed graph and original scale

Any ideas?