Amx=rand(400,300);
Bmx=rand(300,500);
Li=length(Amx(:,1));
LkA=length(Amx(1,:));
[LkB,Lj]=size(Bmx);
tic;
D=zeros(Li, Lj);
for i=1:Li
    for j=1:Lj
        for k=1:LkA
            disp(k);
            D(i,j)=D(i,j)+Amx(i,k)*Bmx(k,j);
        end;
    end;
end;

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tic;
D2=Amx*Bmx;
toc