instantiate a hash
open file of unique keys
while read a line
  get the key from it
  make it a key in your hash, with its value being a reference to an array containing four zeros

for N = 1 to 4
  open file1
    while read a line
      split the key and value out of it
        if the key exists in your hash
          assign the value to your hash as the Nth element of an array referred to by this key
        if the key doesn't exist
          skip it or error, depending on your design

for each key in the hash
  if any of its array's elements are non-zero
      print the key and array elements joined by tabs