KEX13(B)C C C C,KEY TRAPPED EXCHANGE UNIT
KEX13(C)D D D D,KEY TRAPPED EXCHANGE UNIT
KEX13(D)E E E E,KEY TRAPPED EXCHANGE UNIT
KEX13(D)E E F F,KEY TRAPPED EXCHANGE UNIT
KEX13(E)C C C C,KEY TRAPPED EXCHANGE UNIT
KEX13(E)F F F F,KEY TRAPPED EXCHANGE UNIT
KEX13(F)D D D D,KEY TRAPPED EXCHANGE UNIT
KEX13(F)E E E E,KEY TRAPPED EXCHANGE UNIT