#!/bin/bash

lastfile=""
if [[ ! -e "$1/old/" ]]; then
        mkdir "$1/old/"
fi
for file in $(ls -r $1); do
        stripped=$(echo "$file" | cut -d'-' -f1)
        if [[ "$stripped" == "$lastfile" ]]; then
                mv "$1/$file" "$1/old/"
        fi
        lastfile=$stripped
done