%begin
%externalroutinespec prompt(%string (255) s)
! ackerman function
%integer x,y,j,k

%integerfn acker(%integer m,n)
%if m = 0 %then %result = n+1
%if n = 0 %then %result = acker(m-1,1)
%result = acker(m-1, acker(m, n-1))
%end

prompt("Ackerman, First param (1..4)?"); read(x)
prompt("         Second param (1..7)?"); read(y)
write(acker(x,y), 4); newline
%endofprogram