for i=1:Inf
    tmp=input('enter number')
    if tmp >= 0
        A(1,i) = tmp
    end
    else
        break
    end
end

B = zeros(1,length(A));
for i=1:length(A)
    if (A(1,i) ~= 0)
        B(1,i) = A(1,i)^3;
    end
end
B