E2 D1 D2 D3 D4 system C system A system D system B F1 F2 G1 G2 service A2 service A1 service B1 service B2 service C1 service C2 service D1 service D2 service D3 service D4 A1 A2 B1 B2 C1 C3 C2 E1 E2 D1 D2 D3 D4 system C system A system D system B F1 F2 G1 G2 service A2 service A1 service B1 service B2 service C1 service C2 service D1 service D2 service D3 service D4 A1 A2 B1 B2 C1 C3 C2 E1 E2 D1 D2 D3 D4 system C system A system D system B F1 F2 G1 G2 service A2 service A1 service B1 service B2 service C1 service C2 service D1 service D2 service D3 service D4 A1 A2 B1 B2 C1 C3 C2 E1 E2 D1 D2 D3 D4 system C system A system D system B F1 F2 G1 G2 service A2 service A1 service B1 service B2 service C1 service C2 service D1 service D2 service D3 service D4