Letters that make hierarchical structure
s, a, e, l, c, h, r, t, i, u are letters that make 'hierarchical structure'
Words within hierarchical structure
ER, structure, IE, hi, re, ERA, IC, arc, chi, ar, hierarchical, hie, chic, hierarchic, arch, ic, ie, CT, RA, Ur, AL, AR, CA, HI, Ra, Re, hierarch, Al, Ar, Ca, Er, Ru, era are words within 'hierarchical structure'