The attributes of three arithmetic operators in some programming language are given below.

Operator	Precedence	Associativity	Arity
+	High	Left	Binary
_	Medium	Right	Binary
*	Low	Left	Binary

The value of the expression $$2 - 5 + 1 - 7 * 3$$ in this language is _______________.

Consider the following Syntax Directed Translation Scheme $$(SDTS),$$ with non-terminals $$\left\{ {S,A} \right\}$$ and terminals $$\left\{ {A,B} \right\}.$$
$$S \to aA$$ $$\,\,\,\,\,$${ print $$1$$ }
$$S \to a$$ $$\,\,\,\,$$$$\,\,\,\,\,$${ print $$2$$ }
$$A \to Sb$$ $$\,\,\,\,\,$${ print $$3$$ }

Using the above $$SDTS,$$ the output printed by a bottom-up parser, for the input $$aab$$ is:

A sender uses the Stop-and-Wait ARQ protocol for reliable transmission of frames. Frames are of size 1000 bytes and the transmission rate at the sender is 80 Kbps (1Kbps = 1000 bits/second). Size of an acknowledgment is 100 bytes and the transmission rate at the receiver is 8 Kbps. The one-way propagation delay is 100 milliseconds. Assuming no frame is lost, the sender throughput is __________ bytes/second.

An IP datagram of size 1000 bytes arrives at a router. The router has to forward this packet on a link whose MTU (maximum transmission unit) is 100 bytes. Assume that the size of the IP header is 20 bytes.

The number of fragments that the IP datagram will be divided into for transmission is ________.