PROGRAM IS
	TYPE BARRAY IS ARRAY OF BOOLEAN;
	VAR size := 8190;
	VAR IsPrime := BARRAY[<size OF TRUE>];
	VAR i, j, k, prime, count :INTEGER := 0;
	PROCEDURE mark(x :INTEGER) IS
		BEGIN
			IF x < size THEN
				IsPrime[x] := FALSE;
				x := x + prime;
				mark(x);
			END;
		END;


	BEGIN
		WHILE j < size DO
			IF IsPrime[j] = TRUE THEN
				prime := j + j + 3;
				k := j + prime;
				mark(k);
				count := count + 1;
			END;
			j := j + 1;
		END;
		WRITE("The number of prime numbers less than ", size, " is ", count);
	END;