#!/bin/bash
while read x
 do
  y="$y $x"   # build a string y that will contain all file names
 done
for f in $y
  do
    n=$(cat $f | wc -l)
    if [ $n -lt 3 ]  # if there are less than 3 lines in file
      then
       echo $f    # print just file name
       continue   
    fi
    line3=$(head -3 $f1 | tail -1)  # take 3rd line of file
    s=0
    for z in $line3   # calculate sum of numbers in 3rd line of file
     do
      s=$[$s + $z]
     done
    echo "$f $s"
  done