% conductance matrix
G = [2 -1 0 0 0 0;
    -1 1 0 0 0 0;
     0 0 2 -1 0 0;
     0 0 -1 1 0 0;
     0 0 0 0 2 -1;
     0 0 0 0 -1 1];
% capacitance matrix
C = [ 2 0 -1 0 0 0;
    0 1 0 0 0 0;
    -1 0 2 0 0 0;
    0  0 0 2 0 -1;
    0 0 0 0 1 0;
    0 0 0 -1 0 2];
% input & output matrices
F = [ 1 0 0 ; 0 0 0; 0 1 0; 0 0 0; 0 0 1; 0 0 0];
K = [ 0 1 0 0 0 0; 0 0 0 1 0 0; 0 0 0 0 0 1];