Start by naming any country that France borders. Then name any country that borders any of those countries. Then keep going until there are no more countries left to name.
Because Landlocked means it must border an Ocean or Sea (not a lake). I.e. it must have a coastline. Since Michigan only connects to Atlantic via rivers this would not count, as per convention of coastline and landlocked definitions.
isn't Pennsylvania not landlocked though? It borders the Atlantic through the Delaware estuary