). Denote
$$\begin{aligned} &{N_{1}=\bigl[\operatorname{vec}\bigl(\operatorname{Re}(F_{11})\bigr), \operatorname{vec}\bigl(\operatorname{Re}(F_{21})\bigr),\ldots,\operatorname{vec}\bigl( \operatorname{Re}(F_{n1})\bigr), \operatorname{vec}\bigl(\operatorname{Re}(F_{22}) \bigr),\ldots,} \\ &{\hphantom{N_{1}=}\operatorname{vec}\bigl(\operatorname{Re}(F_{n2})\bigr),\ldots,\operatorname{vec}\bigl(\operatorname{Re}(F_{(n-1)(n-1)})\bigr), \operatorname{vec}\bigl( \operatorname{Re}(F_{n(n-1)})\bigr),\operatorname{vec}\bigl(\operatorname{Re}(F_{nn}) \bigr),} \\ &{\hphantom{N_{1}=}\operatorname{vec}\bigl(\operatorname{Re}(G_{21})\bigr),\ldots,\operatorname{vec} \bigl(\operatorname{Re}(G_{n1})\bigr),\operatorname{vec}\bigl(\operatorname{Re}(G_{32})\bigr),\ldots,}\\ &{\hphantom{N_{1}=}\operatorname{vec}\bigl( \operatorname{Re}(G_{n2})\bigr),\ldots,\operatorname{vec}\bigl(\operatorname{Re}(G_{n(n-1)}) \bigr)\bigr],}\\ &{N_{2}=\bigl[\operatorname{vec}\bigl(\operatorname{Im}(F_{11})\bigr), \operatorname{vec}\bigl(\operatorname{Im}(F_{21})\bigr),\ldots,\operatorname{vec}\bigl( \operatorname{Im}(F_{n1})\bigr), \operatorname{vec}\bigl(\operatorname{Im}(F_{22}) \bigr),\ldots,} \\ &{\hphantom{N_{2}=}\operatorname{vec}\bigl(\operatorname{Im}(F_{n2})\bigr),\ldots,\operatorname{vec}\bigl(\operatorname{Im}(F_{(n-1)(n-1)})\bigr), \operatorname{vec}\bigl( \operatorname{Im}(F_{n(n-1)})\bigr),\operatorname{vec}\bigl(\operatorname{Im}(F_{nn}) \bigr),} \\ &{\hphantom{N_{2}=}\operatorname{vec}\bigl(\operatorname{Im}(G_{21})\bigr),\ldots,\operatorname{vec} \bigl(\operatorname{Im}(G_{n1})\bigr),\operatorname{vec}\bigl(\operatorname{Im}(G_{32})\bigr),\ldots,}\\ &{\hphantom{N_{2}=}\operatorname{vec}\bigl( \operatorname{Im}(G_{n2})\bigr),\ldots,\operatorname{vec}\bigl(\operatorname{Im}(G_{n(n-1)}) \bigr)\bigr],}\\ &{N_{3}=\bigl[\operatorname{vec}\bigl(\operatorname{Re}(H_{11})\bigr), \operatorname{vec}\bigl(\operatorname{Re}(H_{21})\bigr),\ldots,\operatorname{vec}\bigl( \operatorname{Re}(H_{n1})\bigr), \operatorname{vec}\bigl(\operatorname{Re}(H_{22}) \bigr),\ldots,} \\ &{\hphantom{N_{3}=}\operatorname{vec}\bigl(\operatorname{Re}(H_{n2})\bigr),\ldots,\operatorname{vec}\bigl(\operatorname{Re}(H_{(n-1)(n-1)})\bigr), \operatorname{vec}\bigl( \operatorname{Re}(H_{n(n-1)})\bigr),\operatorname{vec}\bigl(\operatorname{Re}(H_{nn}) \bigr),} \\ &{\hphantom{N_{3}=}\operatorname{vec}\bigl(\operatorname{Re}(K_{21})\bigr),\ldots,\operatorname{vec} \bigl(\operatorname{Re}(K_{n1})\bigr),\operatorname{vec}\bigl(\operatorname{Re}(K_{32})\bigr),\ldots,}\\ &{\hphantom{N_{3}=}\operatorname{vec}\bigl( \operatorname{Re}(K_{n2})\bigr),\ldots,\operatorname{vec}\bigl(\operatorname{Re}(K_{n(n-1)}) \bigr)\bigr],}\\ &{N_{4}=\bigl[\operatorname{vec}\bigl(\operatorname{Im}(H_{11})\bigr), \operatorname{vec}\bigl(\operatorname{Im}(H_{21})\bigr),\ldots,\operatorname{vec}\bigl( \operatorname{Im}(H_{n1})\bigr), \operatorname{vec}\bigl(\operatorname{Im}(H_{22}) \bigr),\ldots,} \\ &{\hphantom{N_{4}=}\operatorname{vec}\bigl(\operatorname{Im}(H_{n2})\bigr),\ldots,\operatorname{vec}\bigl(\operatorname{Im}(H_{(n-1)(n-1)})\bigr), \operatorname{vec}\bigl( \operatorname{Im}(H_{n(n-1)})\bigr),\operatorname{vec}\bigl(\operatorname{Im}(H_{nn}) \bigr),} \\ &{\hphantom{N_{4}=}\operatorname{vec}\bigl(\operatorname{Im}(K_{21})\bigr),\ldots,\operatorname{vec} \bigl(\operatorname{Im}(K_{n1})\bigr),\operatorname{vec}\bigl(\operatorname{Im}(K_{32})\bigr),\ldots,}\\ &{\hphantom{N_{4}=}\operatorname{vec}\bigl( \operatorname{Im}(K_{n2})\bigr),\ldots,\operatorname{vec}\bigl(\operatorname{Im}(K_{n(n-1)}) \bigr)\bigr].} \end{aligned}$$