MUMPS: 314 chars
L(F,N,R=40,C=80)
N (F,N,R,C)
O F:"RS" U F D C F
.F I=1:1:R R L F J=1:1:C S G(0,I,J)=($E(L,J)="X")
F A=0:1:N-1 F I=1:1:R F J=1:1:C D S G(A+1,I,J)=$S(X=2:G(A,I,J),X=3:1,1:0)
.S X=0 F i=-1:1:1 F j=-1:1:1 I i!j S X=X+$G(G(A,I+i,J+j))
S F="OUT.TXT" O F:"WNS" U F D C F
.F I=1:1:R F J=1:1:C W $S(G(N,I,J):"X",1:".") W:J=C !
Q
