Punchy

In the early days of computing, a program was "punched" onto rectangular cards — one instruction per card. The deck was then fed into a card reader so the program could be read and executed. Fearing that a shuffled deck would ruin their program, students often wrapped an elastic band around the deck and carried it in a box.

Bill was less careful. He left his deck next to an open window, a gust of wind scattered the cards, and now his program is out of order. Bill gathers the cards in whatever order he happens to pick them up and runs the resulting program.

Read Bill's rearranged program and execute the instructions in the order they are given.

Bill's language has only two variables, A and B, and seven kinds of instructions. Both variables start at $0$.

There is exactly one instruction per line. An instruction begins with an integer from $1$ to $7$. Depending on the opcode it may be followed by a variable name, which in turn may be followed by either a number or a variable.

Below, $X$ and $Y$ each denote a variable (A or B); wherever a second operand appears it may instead be a literal integer.

• 1 X n — set variable $X$ to the integer $n$.
• 2 X — output the value of variable $X$.
• 3 X Y — compute $X + Y$ and store the result in $X$.
• 4 X Y — compute $X \times Y$ and store the result in $X$.
• 5 X Y — compute $X - Y$ and store the result in $X$.
• 6 X Y — compute the integer quotient of $X \div Y$, discarding the remainder, and store it in $X$.
• 7 — stop execution.

No division instruction divides by zero, and every computed or stored value stays within $-10000$ to $10000$.

Division truncates toward zero: $-3 \div 2$ and $3 \div -2$ both have quotient $-1$, while $-3 \div -2$ has quotient $1$.

For each output instruction, print the value of the requested variable on its own line, in the order the instructions are executed. Stop as soon as the stop instruction (7) is read.