day2-2.prdc

iIg–Ak{•Hr1h‰‡J¨~HudHL,4/εHt(3%"Q+*"=S{)\Ht~}uPdHu};sHq19690720=}= .. 66 bytes
.. takes a few minutes

{
i   .. read full input
Ig  .. read int groups thereof
–   .. pop and store it into the bullet variable
Ak  .. 10 thousand
{   .. a predicate, given 100 * noun + verb, to see if it works
  •Hr .. put the bullet array, original program, into H, the default hoard
  1h‰ .. divmod the index against 100
  ‡   .. make a length-2 list
  J   .. zip it with its indices
  ¨   .. flatten
  ~   .. expand
  Hud .. do two updates
  HL,4/ .. get indices and break into chunks of 4 and
  ε .. loop for each chunk of indices, same as level 1
    Ht(3%"Q+*"=S{)\Ht~}uPdHu
  }
  ;s  .. pop everything off the stack
  Hq  .. get the first element of the hoard
  19690720= .. is it equal?
}=  .. find the index where this is true
};