#!/bin/sh

input=$1
watermark=$2
output=$3
abl=/tmp/all_but_first.pdf
first=/tmp/first.pdf
first_stamped=/tmp/first_stamped.pdf

# detach
pdftk $1 cat 2-r1 output $abl 
pdftk $1 cat 1 output $first 
#Stamp
pdftk $first stamp $watermark output $first_stamped
#Attach
pdftk $first_stamped $abl cat output $output