function el_obvod
R1=2;R2=3;R3=10;R4=2;R5=1;U01=12;U02=4;
A=[-1,1,1,0,0;...
    0,0,-1,1,1;...
    R1,R2,0,0,0;...
    0,-R2,R3,R4,0;...
    0,0,0,-R4,R5];
disp('Matice koef. soust')
disp(A)
b=[0;0;U01;0;-U02];
disp('Vektor pravych stran')
disp(b)
disp('Determinant')
disp(det(A))
disp('Proudy')
disp(A\b)
end