Delete merged branch in origin not named master, develop or release

gistfile1.txt

$ git remote prune origin && git branch -r --merged | 
  grep origin | 
  grep -v '>' | 
  grep -v 'master' |
  grep -v 'release' |
  grep -v 'develop' |
  xargs -L1 | 
  cut -d"/" -f 2 | 
  xargs git push origin --delete