PROGRAM OISC;

CONST
	MAXADDRESS = 1255;

TYPE
	MEMORY = PACKED ARRAY [0 .. MAXADDRESS] OF INTEGER;

VAR
	MEM : MEMORY;
	FILENAME : STRING;

PROCEDURE LOADTEXT (FILENAME : STRING; VAR MEM : MEMORY);
	VAR
		NUMBERS : TEXT;
		ADDRESS : INTEGER;
	BEGIN
		ASSIGN (NUMBERS, FILENAME);
		ADDRESS := 0;
		RESET (NUMBERS);
		WHILE (ADDRESS <= MAXADDRESS) AND NOT EOF (NUMBERS) DO BEGIN
			READ (NUMBERS, MEM [ADDRESS]);
			ADDRESS := ADDRESS + 1
		END;
		CLOSE (NUMBERS);
		FOR ADDRESS := ADDRESS TO MAXADDRESS DO
			MEM [ADDRESS] := 0
	END;

PROCEDURE SUBLEQ (VAR MEM : MEMORY);
	VAR
		ADDRESS, A, B, C : INTEGER;
		IO : CHAR;
	BEGIN
		ADDRESS := 0;
		WHILE ADDRESS >= 0 DO BEGIN
			A := MEM [ADDRESS];
			B := MEM [ADDRESS + 1];
			C := MEM [ADDRESS + 2];
			ADDRESS := ADDRESS + 3;
			IF A = -1 THEN BEGIN
				READ (IO);
				MEM [B] := ORD (IO)
			END
			ELSE IF B = -1 THEN BEGIN
				IO := CHR (MEM [A]);
				WRITE (IO)
			END
			ELSE BEGIN
				MEM [B] := MEM [B] - MEM [A];
				IF MEM [B] <= 0 THEN ADDRESS := C
			END
		END
	END;

BEGIN
	WRITE ('Filename>');
	READLN (FILENAME);
	LOADTEXT (FILENAME, MEM);
	SUBLEQ (MEM);
END.