.I N<100
.E I N:200
.T S N=149
.T S N0(47)=7
.S N=N++
._ P
.!CLRT
.P "You are at a branch in the tunnel.
.I GE(6):2
.T P "Passages go to the left, right,
.I GE(6):7
.T P "Passages go forward, to the right,
.I GE(6):6
.T P "Passages go forward, to the left,
.P "and back behind you.
!LOOK
.J -10
%L...
.!CLRT
.I GE(6):7
.T J +6
.I GE(6):2
.T S N0(47)=7
.E S N0(47)=2
.P "You turn down the left passage.
.!GTON
.!INVD
%R...
.!CLRT
.I GE(6):6
.T J +6
.I GE(6):2
.T S N0(47)=6
.E S N0(47)=2
.P "You turn down the right passage.
.!GTON
.!INVD
%FW..
.!CLRT
.I GE(6):2
.T J +6
.I GE(6):6
.T S N0(47)=7
.E S N0(47)=6
.P "You continue forward.
.!GTON
.!INVD
%BK..
.!CLRT
.P "You turn around and trudge back down
.P "the passage.
.S GE(6)=N0(47)
.3 ROOM 47.0 
.!TUNL
!GTON
.S GE(6)=N0(N)
.I GE(6)>19
.T S N0(47)=N0(47)+10
.T J +3
.I GE(6)>9
.T S N0(47)=N0(47)+20
.I N>160
.T I TL(23):254
.T S GE(6)=0
.T 3 ROOM 49.0 
.E 3 ROOM 47.0 
.!TUNL
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