#!/bin/sh

prefix="akane_"

for N in {0..100000}
do
  FILE="$prefix$N-0.png"
  if test -f "$FILE"; then
    echo $N;
    magick -delay 10 -loop 0 -dispose previous $(Get-ChildItem $prefix$N-*.png | Sort-Object { [regex]::Replace($_, '\d+', { $args[0].Value.PadLeft(20, '0') }) }) -layers TrimBounds $N.gif
  fi
done