(* Peter Su 1991 *)
SYSTEM scan;

CONST d = 4;
      n = 16;
CONFIGURATION hyper [2], [2], [2], [2];
CONNECTION go(4) : hyper[i,j,k,l] -> hyper [(i+1) mod 2,j,k,l].go(4);
     	   go(3) : hyper[i,j,k,l] -> hyper [i,(j+1) mod 2,k,l].go(3);
     	   go(2) : hyper[i,j,k,l] -> hyper [i,j,(k+1) mod 2,l].go(2);
     	   go(1) : hyper[i,j,k,l] -> hyper [i,j,k,(l+1) mod 2].go(1);


SCALAR k: integer;
       a: ARRAY[1..n] OF integer;

VECTOR val: integer;
 
PROCEDURE plus_scan (VECTOR VAR x: integer);

SCALAR
     i : integer;
    m : integer;

VECTOR
     temp1 : integer;
     temp2 : integer;
     res : integer;
 
BEGIN
     m := 1;
     PARALLEL
           res := x;
           temp1 := x;
     ENDPARALLEL;
     FOR i := 1 TO d DO
     	  PARALLEL 
	            PROPAGATE.go(i) (temp1,temp2);
     	       IF (odd((id_no-1) div m)) THEN
     	       	    res := res + temp2;
     	       END;
     	       temp1 := temp1 + temp2;
     	  ENDPARALLEL;
	       m := m * 2;
     END (* for *);
     PARALLEL
          x := res;
     ENDPARALLEL;

END plus_scan;     
     
BEGIN
     WriteString("Enter "); WriteInt(n,3); WriteString(" numbers."); WriteLn;
     FOR k:=1 TO n DO readint(a[k]) END;
     load(val,a);
     plus_scan(val);
     WriteInt(val,4);

END scan.