ト Katakana "To" or The "Boku" radical - oracle
ニ Katakana "Ni" or NI, futa(tsu), futa - two
ム Katakana "Mu" or The "Mu" radical - private
メ Katakana "Me"
ル Katakana "Ru" or The "Hitoashi" radical - human legs
ロ Katakana "Ro" or KOU, kuchi - mouth
Arrange them like this:
ニム
ルル
ロト
メ
酸 SAN, su(i) - acid, sour