function[K_c,M_c,F_c,nctot]=Constraints(nc,K,M,F)

nctot=zeros(1,numel(nc)*3);

for i=1:numel(nc)
    nctot(i*3-2:i*3)=[nc(i)*3-2 nc(i)*3-1 nc(i)*3];%constrained DOF
end

K(nctot,:)=[];
K(:,nctot)=[];
K_c=K;

M(nctot,:)=[];
M(:,nctot)=[];
M_c=M;

F(nctot)=[];
F_c=F;
return